.ragatouille/colbert/indexes/cbseclass10index/collection.json

[
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-VERY SHORT QUESTIONS.txt\nVery Short Answer Type Question [1 mark]  \nOne Sentence Answer  \n1. What is a redox reaction?  \n2. What is corrosion? Explain its advantage and disadvantage.  \n3. What is rancidity? How can we reduce the problem of rancidity?  \n4. How is corrosion different from rusting?  \n5. What is meant by endothermic and exothermic reactions? Give suitable example \nfor each.  \n6. Define different types of chemical reaction and give examples for each.  \n7. Why is photosynthesis considered as an endothermic reaction?  \n8. In electrolysis of water, why is the volu me of gas collected over one electrode \ndouble that of the other electrode?  \n9. What happens when water is added to solid calcium oxide taken in a container? \nWrite a chemical formula for the same.  \n10. Give three types of decomposition reaction.  \n11. Name the compound us ed for testing CO2-gas.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-VERY SHORT QUESTIONS.txt\nDirection (Q 12 to 16): In the following Questions, the Assertion and Reason have \nbeen put forward. Read the statements carefully and choose the correct \nalternative from the following:",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-VERY SHORT QUESTIONS.txt\n(a) Both the Assertion and Reason are correct and the reason is the correct \nexplanation of the Assertion.  \n(b) The Assertion and the reason are correct but the Reason is not the correct \nexplanation of the Assertion.  \n(c) Assertion is true but the Reason is false.  \n(d) The statement of the Assertion is false but the reason is true.  \n12. Assertion  : AgBr is used on photographic and X -ray film  \nReason    :  AgBr is photosensitive and changes to Ag and bromine in presence  \n                    of   sunlight and undergoes decomposition reaction.  \n13. Assertion:  Magnesium ribbon keeps on burning in atmosphere of nitrogen.  \nReason    :  Magnesium reacts with nitrogen to form magnesium nitride and  \n                    this    reaction is combination reaction . \n14. Assertion  :Zinc reacts with sulphuric acid to form to form zinc sulphate and  \n                    Hydrogen gas and it is displacement reaction.  \nReason      : Zinc reacts with oxygen to form Zinc oxide",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-VERY SHORT QUESTIONS.txt\nHydrogen gas and it is displacement reaction.  \nReason      : Zinc reacts with oxygen to form Zinc oxide  \n15. Assertion :  MnO 2 + 4 HCl ---\uf0e0 MnCl 2 + Cl 2 + 2 H 2O is r edox reaction.  \nReason    :   MnO 2 oxides HCl to Cl 2 and gets reduced to MnCl 2 \n16. Assertion  :  lead nitrate on thermal decomposition gives lead oxide , brown  \n                     coloured    nitrogen dioxide and oxygen gas .  \nReason     : Lead nitrate reacts wi th potassium iodide to form yellow ppt of lead \niodide  \n                   And the reaction is double displacement as well as precipitation \nreaction.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-MCQ.txt\nChemical Reactions and Equations  \nMCQ  Type Questions  \n1. Some crystal s of copper sulphate were dissolved in water. The colour of the \nsolution obtained would be  \n(a) Green  \n(b) Red \n(c) Blue \n(d) Brown  \n2. When dilute HCl is added to zinc pieces taken in a test tube  \n(a) No change take place  \n(b) The colour of the solution becomes yellow  \n(c) A pungent smelling gas gets liberated  \n(d) A small bubbles of H2 gas appear on the surface of zinc pieces.  \n3. PbS reacts with ozone (O3) and forms PbSO4. As per the balanced equation, \nmolecues of ozone required for e very one molecule of PbS is/are  \n(a) 4 \n(b) 3 \n(c) 2 \n(d) 1 \n4. Chemically rust is  \n(a) Hydrated ferrous oxide  \n(b) Hydrated ferric oxide  \n(c) Only ferric oxide  \n(d) None of these  \n5.",
  "Chemically rust is  \n(a) Hydrated ferrous oxide  \n(b) Hydrated ferric oxide  \n(c) Only ferric oxide  \n(d) None of these  \n5. Which of the following reactions is not correct  \n(a) Zn + CuSO 4 -----\uf0e0 ZnSO 4 +Cu \n(b) 2 Ag + Cu(NO 3)2  --\uf0e0 2 AgNO 3 + Cu  \n(c) Fe + CuSO 4 -\uf0e0 FeSO 4 + Cu  \n(d) Mg + 2 HCl  ---\uf0e0 MgCl 2 + H 2",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-MCQ.txt\n5. Which of the following reactions is not correct  \n(a) Zn + CuSO 4 -----\uf0e0 ZnSO 4 +Cu \n(b) 2 Ag + Cu(NO 3)2  --\uf0e0 2 AgNO 3 + Cu  \n(c) Fe + CuSO 4 -\uf0e0 FeSO 4 + Cu  \n(d) Mg + 2 HCl  ---\uf0e0 MgCl 2 + H 2 \n6. Copper displaces which of the following metals from its salt solution:  \n(a) ZnSO 4 \n(b) FeSO 4 \n(c) AgNO 3 \n(d) NiSO 4 \n7. In an electric cell where electrolysis is carried out , anode has:  \n(a) Positive charge  \n(b) Negative charge  \n(c) Connected to negative terminal of the battery  \n(d) None of these is correct  \n8. The reaction H 2 + Cl 2  --\uf0e0 2 HCl represents:  \n(a) oxidation  \n(b) reduction  \n(c) decomposition  \n(d) combination  \n9.",
  "The reaction H 2 + Cl 2  --\uf0e0 2 HCl represents:  \n(a) oxidation  \n(b) reduction  \n(c) decomposition  \n(d) combination  \n9. In the reaction PbO + C --\uf0e0 Pb + CO  \n(a) PbO is oxidized  \n(b) C act as an oxidizing agent  \n(c) C act as a reducing agent  (d) Reaction does not represent redox reaction  \n10. A substance which oxidizes itself and reduces other is known as  \n(a) Oxidizing agent  \n(b) Reducing agent  \n(c) Both (a) and (b)  \n(d) None of these.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-MCQ.txt\n10. A substance which oxidizes itself and reduces other is known as  \n(a) Oxidizing agent  \n(b) Reducing agent  \n(c) Both (a) and (b)  \n(d) None of these.  \n11. Take about 5 ml of dil.HCl in a test tube and add a few pieces of fine granules \nof zinc in it. Which gas is evolved?  \n(a) Chlorine  \n(b) Hydrogen  \n(c) HCl \n(d) Nitrogen  \n12. Dissolving sugar is an example of:  \n(a) Physical change  \n(b) Chemical change  \n(c) Redox reaction  \n(d) None of these  \n13. Heat is evolved during:  \n(a) Endother mic reaction  \n(b) Displacement reaction  \n(c) Combustion reaction  \n(d) Combination reaction  \n14. Which of the following is not a balanced equation?",
  "Heat is evolved during:  \n(a) Endother mic reaction  \n(b) Displacement reaction  \n(c) Combustion reaction  \n(d) Combination reaction  \n14. Which of the following is not a balanced equation?  \n(a) Fe + Cl 2 ----\uf0e0 FeCl 3 \n(b) Mg + CuSO 4 -----\uf0e0 MgSO 4 +Cu \n(c) NaOH + HCl --\uf0e0 NaCl + H 2O \n(d) Zn + S -\uf0e0 ZnS \n15. The reaction between lead nitrate and potassium iodide present in aqueous \nsolution is an example of  \n(a) Decomposition reaction  \n(b) Displacement reation  \n(c) Double displacement reaction  \n(d) Neutralization reaction",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-MCQ.txt\nsolution is an example of  \n(a) Decomposition reaction  \n(b) Displacement reation  \n(c) Double displacement reaction  \n(d) Neutralization reaction  \n16. What happens when dilute hydrochloric acid is added to iro n filings?  \n(a) hydrogen gas and iron chloride are produced  \n(b) chlorine gas and iron hydroxides are produced  \n(c) no reaction takes place  \n(d) iron salt and water are produced.  \n17. Which of the following gases can be used for the storage of fresh sample of \nan oil for a longer time?  \n(a) Carbon dioxide or oxygen  \n(b) Nitrogen or helium  \n(c) Helium or oxygen  \n(d) Nitrogen or oxygen.  \n18. In the decomposition of lead (II) nitrate to give lead (II) oxide, nitrogen dioxide \nand oxygen gas, the coefficient of nitrogen dioxide ( in the balanced equation) \nis \n(a) 1 \n(b) 2 \n(c) 3 (d) 4 \n19.",
  "In the decomposition of lead (II) nitrate to give lead (II) oxide, nitrogen dioxide \nand oxygen gas, the coefficient of nitrogen dioxide ( in the balanced equation) \nis \n(a) 1 \n(b) 2 \n(c) 3 (d) 4 \n19. We store silver chloride in dark coloured bottles because it is  \n(a) A white solid  \n(b) Undergoes redox reaction  \n(c) To avoid action by sunlight  \n(d) None of the above.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-MCQ.txt\n(b) 2 \n(c) 3 (d) 4 \n19. We store silver chloride in dark coloured bottles because it is  \n(a) A white solid  \n(b) Undergoes redox reaction  \n(c) To avoid action by sunlight  \n(d) None of the above.  \n20. Silver articles turn blak when kept in the open for a few days due to formation \nof  \n(a) H2S \n(b) AgS \n(c) AgSO 4 \n(d) Ag2S",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nChapter 1  \nCHEMICAL REACTIONS AND EQUATIONS  \nChem ical Reaction: The tra nsformation  of chemical substance into another \nchemical substance is known as Chemical Reaction.  \nFor example: Rusting of iron, the setting of milk into curd, digestion of food, \nrespiration, etc.  \nIn a chemical reaction, a new substance is formed which is completely different in \nproperties from the original substance, so in a chemical reaction, a chemical change \ntakes place.  \nOnly a rearrangement of atoms takes place in a chemical r eaction.  \n\u2022 The substances which take part in a chemical reaction are called  reactants.  \n\u2022 The new substances produced as a result of a chemical reaction are called \nproducts.  \nExample:  The burning of magnesium in the air to form magnesium oxide is an \nexample of a  chemical reaction.  \n                         2Mg(s) + O 2(g)  2MgO(s)  \nBefore burning in air, the magnesium ribbon is cleaned by rubbing with sandpaper.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nexample of a  chemical reaction.  \n                         2Mg(s) + O 2(g)  2MgO(s)  \nBefore burning in air, the magnesium ribbon is cleaned by rubbing with sandpaper.  \nThis is done to remove the protective layer of basic magnesium carbonate from the \nsurface of the magnesi um ribbon.  \nReactant:  Substances which take part in a chemical reaction are called reactants.  \nExample: Mg and O 2. \nProduct:  New substance formed after a chemical reaction is called a product.  \nExample: MgO.  \nCharacteristics of Chemical Reactions:  \n(i) Evolution of gas:  The chemical reaction between zinc and dilute sulphuric acid is \ncharacterised by the evolution of hydrogen gas.  \n                   Zn(s) + H 2SO 4(aq) \u2192 ZnSO 4(aq) + H 2(g) \u2191 \n(ii) Change in Colour:  The chemical reacti on between citric acid and purple \ncoloured potassium permanganate solution is characterised by a change in colour \nfrom purple to colourless.",
  "The chemical reaction between sulphur dioxide gas and acidified potassium",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\ncoloured potassium permanganate solution is characterised by a change in colour \nfrom purple to colourless.  \nThe chemical reaction between sulphur dioxide gas and acidified potassium \ndichromate solution is characterized by a  change in colour from orange to green.  \n(iii) Change in state of substance:  The combustion reaction of candle wax is \ncharacterised by a change in state from solid to liquid and gas (because the wax is a \nsolid, water formed by the combustion of wax is a liq uid at room temperature \nwhereas, carbon dioxide produced by the combustion of wax is a gas). There are \nsome chemical reactions which can show more than one characteristics.  \n(iv) Change in temperature:  The chemical reaction between quick lime water to \nform slaked lime is characterized by a change in temperature (which is a rise in \ntemperature).  \nThe chemical reaction between zinc granules and dilute sulphuric acid is also \ncharacterised by a change in temperature (which is a rise in temperature).",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\ntemperature).  \nThe chemical reaction between zinc granules and dilute sulphuric acid is also \ncharacterised by a change in temperature (which is a rise in temperature).  \n(v) Formation  of precipitate:  The chemical reaction between sulphuric acid and \nbarium chloride solution is characterised by the formation of a white precipitate of \nbarium sulphate.  \n    BaCl 2(aq) + H 2SO 4(aq) \u2192 BaSO 4(s) (ppt) + 2HCl(aq)  \nWhat is a chemical Equation  \nChemical Equation:  Representation of chemical reaction using symbols and \nformulae of the substances is called Chemical Equation.  \nExample: A + B \u2192 C + D  \nIn this equation, A and B are called reactants and C and D are called the p roducts. \nThe arrow shows the direction of the chemical reaction. Condition, if any, is written \ngenerally above the arrow.  \nWhen hydrogen reacts with oxygen, it gives water. This reaction can be represented \nby the following chemical equation:  \n        Hydroge n + Oxygen \u2192 Water",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\ngenerally above the arrow.  \nWhen hydrogen reacts with oxygen, it gives water. This reaction can be represented \nby the following chemical equation:  \n        Hydroge n + Oxygen \u2192 Water  \n                    H2 + O 2          \u2192 H 2O \nIn the first equation, words are used and in second, symbols of substances are used \nto write the chemical equation. For convenience, the symbol of substance is used to \nrepresent chemical equatio ns. \nA chemical equation is a way to represent the chemical reaction in a concise and \ninformative way.  \nA chemical equation can be divided into two types: Balanced Chemical Equation and \nUnbalanced Chemical Equation.  \n(a) Balanced Chemical Equation:  A balanced  chemical equation has the number of \natoms of each element equal on both sides.  \nExample: Zn + H 2SO 4 \u2192 ZnSO 4 + H 2 \nIn this equation, numbers of zinc, hydrogen and sulphate are equal on both sides, so \nit is a Balanced Chemical Equation.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nExample: Zn + H 2SO 4 \u2192 ZnSO 4 + H 2 \nIn this equation, numbers of zinc, hydrogen and sulphate are equal on both sides, so \nit is a Balanced Chemical Equation.  \nAccording to the Law of Conservation of Mass, mass can neither be created nor \ndestroyed in a chemical reaction. To obey this law, the total mass of elements \npresent in reactants must be equal to the total mass of elements present in products.  \n(b) Unbalanced Chemical Equation:  If the number of atoms of each element in \nreactants is not equal to the number of atoms of each element present in the product, then the chemical equation is called Unbalanced Chemical Equation.  \nExample: Fe + H 2O \u2192 Fe 3O4 + H 2 \nIn this exa mple, a number of atoms of elements are not equal on two sides of the \nreaction. For example; on the left -hand side only one iron atom is present, while \nthree iron atoms are present on the right -hand side. Therefore, it is an unbalanced \nchemical equation.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nreaction. For example; on the left -hand side only one iron atom is present, while \nthree iron atoms are present on the right -hand side. Therefore, it is an unbalanced \nchemical equation.  \nBalancing a Chemical Equation: To balance the given or any chemical equation, \nfollow these steps:  \nFe + H 2O \u2192 Fe 3O4 + H 2 \nWrite the number of atoms of elements present in reactants and in products in a \ntable as shown here.  \nName of atom  No. of atoms in the rea ctant  No. of atoms in the product  \nIron 1 3 \nHydrogen  2 2 \nOxygen  1 4 \nBalance the atom which is maximum in number on either side of a chemical \nequation.  \nIn this equation, the number of oxygen atom is the maximum on the RHS.  \nTo balance the oxygen, one needs to multiply the oxygen on the LHS by 4, so that, \nthe number of oxygen atoms becomes equal on both sides.",
  "In this equation, the number of oxygen atom is the maximum on the RHS.  \nTo balance the oxygen, one needs to multiply the oxygen on the LHS by 4, so that, \nthe number of oxygen atoms becomes equal on both sides.  \nFe + 4 \u00d7 H 2O \u2192 Fe 3O4 + H 2 \nNow, the number of hydrogen atoms becomes 8 on the LHS, which is more than that",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nthe number of oxygen atoms becomes equal on both sides.  \nFe + 4 \u00d7 H 2O \u2192 Fe 3O4 + H 2 \nNow, the number of hydrogen atoms becomes 8 on the LHS, which is more than that \non the RHS. To balance it, one needs to  multiply the hydrogen on the RHS by 4.  \nFe + 4 \u00d7 H 2O \u2192 Fe 3O4 + 4 \u00d7 H 2 \nAfter that, the number of oxygen and hydrogen atoms becomes equal on both sides. \nThe number of iron is one on the LHS, while it is three on the RHS. To balance it, \nmultiply the iron on t he LHS by 3.  \n3 \u00d7 Fe + 4 \u00d7 H 2O \u2192 Fe 3O4 + 4 \u00d7 H 2 \nNow the number of atoms of each element becomes equal on both sides. Thus, this \nequation becomes a balanced equation.  Name of atom   \nNo. of atoms in the reactant  \n No.",
  "Thus, this \nequation becomes a balanced equation.  Name of atom   \nNo. of atoms in the reactant  \n No. of atoms in the product  \nIron 3 3 \nHydrogen  8 8 \nOxygen  4 4 \nAfter balancing, the above equation can be written as follows:  \n3Fe + 4H 2O \u2192 Fe 3O4 + 4H 2. \nTo Make Equations More Informative:  \nWriting the symbols of physical states of substances in a chemical equation:",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\n3Fe + 4H 2O \u2192 Fe 3O4 + 4H 2. \nTo Make Equations More Informative:  \nWriting the symbols of physical states of substances in a chemical equation:  \nBy writing the physical states of substances, a chemical equation becomes more \ninformative.  \n\u2022 Gaseous state is represented by symbol (g).  \n\u2022 Liquid state is represented by symbol (l).  \n\u2022 Solid state is written by symbol (s).  \n\u2022 Aqueous solution is written by symbol (aq).  \n\u2022 Writing the condition in which reaction takes place: The condition is generally \nwritten above and/or below the arrow of a chemical equation.  \nThus, by writing the symbols of the physical state of substances and condition under \nwhich reaction takes place, a chemical equation can be made more informative.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nWhat are the types of a chemical reaction  Types of Chemical Reactions:  Combination Reaction, Decomposition Reaction, \nDisplacement Reaction, Double Displacement Reaction, Neutralization Reactions, \nExothermic \u2013 Endothermic Reactions and Oxidation -Reduction Reactions.  \nTypes of Chemical Reactions:  \nChemical reactions can be classified in following types:  \n(i) Combination Reaction:  Reactions in which two or more reactants combine to \nform one product are c alled Combination Reactions.  \nA general combination reaction can be represented by the chemical equation given \nhere:  \n         A + B \u2192 AB  \nExamples:  \nWhen magnesium is burnt in the air (oxygen), magnesium oxide is formed. In this \nreaction, magnesium is combine d with oxygen.  \n               2Mg(s) + O 2(g) \u2192 2MgO(s)  \n             Magnesium + Oxygen \u2192 Magnesium Oxide  \nWhen carbon is burnt in oxygen (air), carbon dioxide is formed. In this reaction, \ncarbon is combined with oxygen.",
  "2Mg(s) + O 2(g) \u2192 2MgO(s)  \n             Magnesium + Oxygen \u2192 Magnesium Oxide  \nWhen carbon is burnt in oxygen (air), carbon dioxide is formed. In this reaction, \ncarbon is combined with oxygen.  \nC (s) + O 2(g) \u2192 CO 2(g)",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nMagnesium + Oxygen \u2192 Magnesium Oxide  \nWhen carbon is burnt in oxygen (air), carbon dioxide is formed. In this reaction, \ncarbon is combined with oxygen.  \nC (s) + O 2(g) \u2192 CO 2(g) \nCarbon + Oxyge n \u2192 Carbon dioxide  \n(ii) Decomposition Reaction:  Reactions in which one compound decomposes in \ntwo or more compounds or elements are known as Decomposition Reaction. A \ndecomposition reaction is just the opposite of combination reaction.  \nA general decomposit ion reaction can be represented as follows:  \n                        AB \u2192 A + B  \nExamples:  \nWhen calcium carbonate is heated, it decomposes into calcium oxide and carbon \ndioxide.",
  "A \ndecomposition reaction is just the opposite of combination reaction.  \nA general decomposit ion reaction can be represented as follows:  \n                        AB \u2192 A + B  \nExamples:  \nWhen calcium carbonate is heated, it decomposes into calcium oxide and carbon \ndioxide.  \nCaCO 3(s)  CaO(s) + CO 2(g) \nCalcium carbonate \u2192 Calcium oxide + Carbon dioxide  \nWhen ferric hydroxide is heated, it decomposes into ferric oxide and water  \n              2Fe(OH) 3(s)  Fe 2O3(s) + 3H 2O(l) \nThermal Decomposition:  The decomposition of a substance on heating is known \nas Thermal Decomposition.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\n2Fe(OH) 3(s)  Fe 2O3(s) + 3H 2O(l) \nThermal Decomposition:  The decomposition of a substance on heating is known \nas Thermal Decomposition.  \nExample: 2Pb(NO 3)2(s)  2PbO(s) + 4NO 2(g) + O 2(g) \nElectrolytic Decomposition:  Reactions in which compounds decompose into \nsimpler compounds because of passing of electricity, are known as Electrolytic \nDecomposition. This is also known as Electrolysis.  \nExample: When electricity is passed in water, it decomposes into hydrogen and \noxygen.  \n      2H 2O(l)  2H 2(g) + O 2(g) \nPhotolysis or Photo Decomposition Reaction:  Reactions in which a compound \ndecomposes because of sunlight are known as Photolysis or Photo Decomposition \nReaction.",
  "2H 2O(l)  2H 2(g) + O 2(g) \nPhotolysis or Photo Decomposition Reaction:  Reactions in which a compound \ndecomposes because of sunlight are known as Photolysis or Photo Decomposition \nReaction.  \nExample: When silver chloride is put in sunlight, it decomposes into silver metal and \nchlorine gas.  \n           2AgCl(s) (white)   2Ag(s) (grey) + Cl 2(g) \nPhotographic paper has a coat of silver chloride, which turns into grey when exposed",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nchlorine gas.  \n           2AgCl(s) (white)   2Ag(s) (grey) + Cl 2(g) \nPhotographic paper has a coat of silver chloride, which turns into grey when exposed \nto sunlig ht. It happens because silver chloride is colourless while silver is a grey \nmetal.  \n(iii) Displacement Reaction:  The chemical reactions in which a more reactive \nelement displaces a less reactive element from a compound is known as \nDisplacement Reactions. Displacement reactions are also known as Substitution \nReaction or Single Displacement/ replacement reactions.  \nA general displacement reaction can be represented by using a chemical equation \nas follows :  \n                    A + BC \u2192 AC + B  \nDispla cement reaction takes place only when \u2018A\u2019 is more reactive than B. If \u2018B\u2019 is \nmore reactive than \u2018A\u2019, then \u2018A\u2019 will not displace \u2018C\u2019 from \u2018BC\u2019 and reaction will not be \ntaking place.  \nExamples:  \nWhen zinc reacts with hydrochloric acid, it gives hydrogen gas an d zinc chloride.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\ntaking place.  \nExamples:  \nWhen zinc reacts with hydrochloric acid, it gives hydrogen gas an d zinc chloride.  \n                      \n                   Zn(s) + 2HCl(aq) \u2192 ZnCl 2(aq) + H 2(g) \nWhen zinc reacts with copper sulphate, it forms zinc sulphate and copper metal.  \n                 \n                  Zn(s) + CuSO 4(aq) \u2192 ZnSO 4(aq) + Cu(s)  \n(iv) Double Displacement Reaction:  Reactions in which ions are exchanged \nbetween two reactants forming new compounds are called Double Displacement \nReactions.  \n              AB + CD \u2192 AC + BD  \nExamples:  \nWhen the solution of barium chloride reacts with the solutio n of sodium sulphate, \nwhite precipitate of barium sulphate is formed along with sodium chloride.",
  "AB + CD \u2192 AC + BD  \nExamples:  \nWhen the solution of barium chloride reacts with the solutio n of sodium sulphate, \nwhite precipitate of barium sulphate is formed along with sodium chloride.  \n             \n               BaCl 2(aq) + Na 2SO 4(aq) \u2192 BaSO 4(s) (Precipitate) + 2NaCl(aq)  \nWhen sodium hydroxide (a base) reacts with hydrochloric acid, sodium chloride and \nwater are formed.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nNaOH(aq) + HCl(aq) \u2192 NaCl(aq) + H 2O(l) \nNote: Double Displacement Reaction, in which precipitate is formed, is also known \nas precipitation reaction. Neutralisation reactions are also examples of double \ndisplacement reaction.  \nPrecipitation Reaction:  The reaction in which precipitate is formed by the mixing of \nthe aqueous solution of two salts is called Precipitation Reaction.  \nExample:  \n \nNeutralization Reaction:  The reaction in which an acid reacts with a base to form \nsalt and water by an exchange of ions is called Neutralization Reaction.  \nExample:",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\n(v) Oxidation and Reduction Reactions:  \nOxidation:  Addition of oxygen or non -metallic element or removal of hydrogen or \nmetallic element from a compound is known as Oxidation.  \nElements or compounds in which oxygen or non -metallic element is added or \nhydrogen or metallic element is removed are called to be oxidized . \nReduction:  Addition of hydrogen or metallic element or removal of oxygen or non -\nmetallic elemen t from a compound is called Reduction.  \nThe compound or element which goes under reduction in called to be reduced . \nOxidation and Reduction take place together.  \nOxidizing agent:  \n\u2022 The substance which gives oxygen for oxidation is called an Oxidizing agent.  \n\u2022 The substance which removes hydrogen is also called an Oxidizing agent.  \nReducing agent:  \n\u2022 The substance which gives hydrogen for reduction is called a Reducing agent.  \n\u2022 The substance which removes oxygen is also called a Reducing agent.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nReducing agent:  \n\u2022 The substance which gives hydrogen for reduction is called a Reducing agent.  \n\u2022 The substance which removes oxygen is also called a Reducing agent.  \nThe reaction in which oxi dation and reduction both take place simultaneously is \ncalled Redox reaction.  \nWhen copper oxide is heated with hydrogen, then copper metal and hydrogen are \nformed.  \nCuO + H 2 \u2192 Cu + H 2O \n(i) In this reaction, CuO is changing into Cu. Oxygen is being removed f rom copper \noxide. Removal of oxygen from a substance is called Reduction, so copper oxide is \nbeing reduced to copper.  \n(ii) In this reaction, H 2 is changing to H 2O. Oxygen is being added to hydrogen. \nAddition of oxygen to a substance is called Oxidation, so  hydrogen is being oxidised \nto water.  \n\u2022 The substance which gets oxidised is the reducing agent.  \n\u2022 The substance which gets reduced is the oxidizing agent.  \n(vi) Exothermic and Endothermic Reactions:",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nto water.  \n\u2022 The substance which gets oxidised is the reducing agent.  \n\u2022 The substance which gets reduced is the oxidizing agent.  \n(vi) Exothermic and Endothermic Reactions:  \nExothermic Reaction:  Reaction which produces energy is called Exothermic \nReaction. Most of the decomposition reactions are exothermic.  \nExample:  \nRespiration is a decomposition reaction in which energy is released.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nWhen quick lime (CaO) is added to water, it releases energy.  \n \nEndothermic Reaction:  A chemi cal reaction in which heat energy is absorbed is \ncalled Endothermic Reaction.  \nExample: Decomposition of calcium carbonate.  \n \nEffects of Oxidation Reactions in Everyday life:  Corrosion and Rancidity.  \nCorrosion:  The process of slow conversion of metals i nto their undesirable \ncompounds due to their reaction with oxygen, water, acids, gases etc. present in the \natmosphere is called Corrosion.  \nExample: Rusting of iron.  \n \n \nRusting:  Iron when reacts with oxygen and moisture forms red substance which is \ncalled Rust .",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nRusting:  Iron when reacts with oxygen and moisture forms red substance which is \ncalled Rust . \n \nThe rusting of iron is a redox reaction.  \nCorrosion (rusting) weakens the iron and steel objects and structures such as \nrailings, car bodies, bridges and ships etc. and cuts short their life.  \nMethods to Prevent Rusting  \n\u2022 By painting.  \n\u2022 By greasing and oilin g. \n\u2022 By galvanisation.  \nCorrosion of Copper:  Copper objects lose their lustre and shine after some time \nbecause the surface of these objects acquires a green coating of basic copper \ncarbonate, CuCO 3.Cu(OH) 2 when exposed to air.",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nCorrosion of Silver Metal:  The surface of silver metal gets tarnished (becomes dull) \non exposure to air, due to the formation of a coating of black silver sulphide(Ag 2S) on \nits surface by the action of H 2S gas present in the air.  \n     \n                   2 Ag(s) + H 2S -------- ----\u2192 Ag2S  + H 2 \nRancidity:  The taste and odour of food materials containing fat and oil changes \nwhen they are left exposed to air for a long time. This is called Rancidity. It is caused \ndue to the oxidation of fat and oil present in food materials.  \nMethods to prevent rancidity:  \n\u2022 By adding anti -oxidant.  \n\u2022 Vacuum packing.  \n\u2022 Replacing air by nitrogen.  \n\u2022 Refrigeration of foodstuff.  \nQuick Notes  \n1. Chemical Reaction:  During chemical reactions, the chemical composition of \nsubstances changes or new substances are formed.  \n2.",
  "\u2022 Vacuum packing.  \n\u2022 Replacing air by nitrogen.  \n\u2022 Refrigeration of foodstuff.  \nQuick Notes  \n1. Chemical Reaction:  During chemical reactions, the chemical composition of \nsubstances changes or new substances are formed.  \n2. Chemical Equation:  Chemical reactions can be written in chemical equation form \nwhich should always be balanced.  \n3. Types of Chemical Reactions:",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\n2. Chemical Equation:  Chemical reactions can be written in chemical equation form \nwhich should always be balanced.  \n3. Types of Chemical Reactions:  \nCombination reaction:  A single product is formed from two or more reactants.  \n2Mg + O 2 \u2192 2MgO  \nDecomposition reaction:  A single reactant breaks down to yield two or more \nproducts.  \n\u2022 Thermal decomposition:  2Pb(NO 2)2 \u2192 2PbO + 4NO 2 + O 2 \n\u2022 Electrolysis:  2H20 \u2192 2H 2 + O 2 \n\u2022 Photochemical reaction:  2AgBr \u2192 2Ag + Br 2 \nDisplacement reaction:  One element is displaced by another element.  \nZn + CuSO 4 \u2192 ZnSO 4 + Cu  \nDouble displacement reaction:  Exchange of ions between reactants.  \nAgNO 3 + NaCl \u2192 AgCl + NaNO 3 \nRedox reaction:  Both oxidation and reduction take place simultaneously.",
  "Zn + CuSO 4 \u2192 ZnSO 4 + Cu  \nDouble displacement reaction:  Exchange of ions between reactants.  \nAgNO 3 + NaCl \u2192 AgCl + NaNO 3 \nRedox reaction:  Both oxidation and reduction take place simultaneously.  \nCuO + H 2 \u2192 Cu + H 2O \nExothermic reaction:  A chemical reaction in which heat energy is evolved.  \nC + O 2 \u2192 CO 2 (g) + heat  \nEndothermic reaction:  A chemical reaction in which heat energy is absorbed.  \nZnCO 3 + Heat \u2192 ZnO + CO 2",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nC + O 2 \u2192 CO 2 (g) + heat  \nEndothermic reaction:  A chemical reaction in which heat energy is absorbed.  \nZnCO 3 + Heat \u2192 ZnO + CO 2 \nRedox reaction:  Chemical reaction in which both oxidation  and reduction take place \nsimultaneously.  \n4. Oxidation:  Reaction that involves the gain of oxygen or loss of hydrogen.  \n5. Reduction:  Reaction that shows the loss of oxygen or gain of hydrogen.  \nZnO + C \u2192 Zn + CO  \nZnO is reduced to Zn \u2014reduction. C is oxidized  to CO \u2014Oxidation.  \n6. Effects of Oxidation Reactions in Our Daily Life:  \n\u2022 Corrosion:  It is an undesirable change that occurs in metals when they are \nattacked by moisture, air, acids and bases.  \nExample, Corrosion (rusting) of Iron: Fe 2O3.",
  "Effects of Oxidation Reactions in Our Daily Life:  \n\u2022 Corrosion:  It is an undesirable change that occurs in metals when they are \nattacked by moisture, air, acids and bases.  \nExample, Corrosion (rusting) of Iron: Fe 2O3. nH 2O (Hydrated iron oxide)  \u2022 Rancidity:  Undesirable change that takes place in oil containing food items \ndue to the oxidation of fatty acids.  \nPreventive methods of rancidity: Adding antioxidants to the food materials,",
  "CHAPTER 1 -CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\ndue to the oxidation of fatty acids.  \nPreventive methods of rancidity: Adding antioxidants to the food materials, \nstoring food in the airtight container, flush ing out air with nitrogen gas and \nrefrigeration.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\nChemical Reactions and Equations  \nCompetency Based Questions",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\n1. A compound 'X'  used  for drinking, has pH =7. Its acidified solution \nundergoes decomposition in presence of electricity to produce gases ' \nY' and 'Z' The volume of Y is double than Z. Y is highly combustible \nwhereas Z is supporter of combustion. identify X. Y & Z and write th e \nchemical reactions involved.  \n2. An aqueous solution of metal nitrate P reacts with sodium bromide \nsolution to form yellow not of compound O which is used in \nphotography. O on exposure to sunlight undergoes decomposition \nreaction to form metal present in P a long with reddish brown gas. \nIdentify P & O. Write the chemical reaction & type of chemical reaction.  \n3. Bhawana took a pale green substance A in a test tube, and heated it \nover the flame of a burner. A brown coloured  residue B was formed \nalong with evolution  of two gases with burning smell of sulphur. Identify \nA & B. Write the chemical reaction involved.  \n4.",
  "A brown coloured  residue B was formed \nalong with evolution  of two gases with burning smell of sulphur. Identify \nA & B. Write the chemical reaction involved.  \n4. A student took 2 -3 g of a substance X in a glass beaker & poured water",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\nalong with evolution  of two gases with burning smell of sulphur. Identify \nA & B. Write the chemical reaction involved.  \n4. A student took 2 -3 g of a substance X in a glass beaker & poured water \nover it slowly. He observed bubbles along with hissing noise. The \nbeaker becomes quite  hot. Identify X. What type of reaction is it?  \n5. A substance X used for coating iron articles is added to a blue solution \nof a reddish brown metal Y. The colour  of the solution gets discharged . \nIdentify X and Y & also the type of reaction.  \n6. A reddish brown ve ssel developed a green coloured  solid X when left \nopen in air for a long time. When reacted with dil H 2S04.",
  "Identify X and Y & also the type of reaction.  \n6. A reddish brown ve ssel developed a green coloured  solid X when left \nopen in air for a long time. When reacted with dil H 2S04. it forms a blue \ncoloured  solution along with brisk effervescence due to colourless & \nodourless gas Z. X decomposes to form black coloured  oxide Y of  a \nreddish brown metal along with gas Z. Identify X. Y. & Z.  \n7. A student has mixed the solutions of lead (II) nitrate and potassium \niodide,",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\nreddish brown metal along with gas Z. Identify X. Y. & Z.  \n7. A student has mixed the solutions of lead (II) nitrate and potassium \niodide,  \n(i) What was the colour of the precipitate fo rmed? Can you name the \ncompound  precipitated?  \n(ii) Write the balanced chemical  equation for this reaction,  \n(iii) What type of reaction is it?  8. Observe the following activity & answer the Questions",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\na. Do you observe anything happening around the zinc granules  \nb. Is there any change in its temperature?  \nc. Why is glass tube not dipp ed in dil H 2SO 4? \nd. How is H 2 gas collected by downward displacement or upward \ndisplacement of water?  \ne. Is H 2 gas soluble or insoluble in water?  \nf. Is H 2 gas heavier or lighter than air?  \n9. A reddish brown metal X when heated in presence of oxygen forms a \nblack compound Y which is ba sic in nature when heated with hydrogen \ngas gives back X. Identify X & Y. Write the chemical reaction between Y \n& H 2 .Identify the substance being oxidized & reduced  \n10. Name the type of reaction seen in the diagram  below. Write the equation  \nfor the  reaction.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\n11. A student burnt a metal A found in the form of ribbon. The ribbon burnt \nwith a dazzling flame & a white powder B is formed which is basic in \nnature. Identify A & B. Write the balanced chemical equation.  \n12. A student drop ped few p ieces of marble in dilute H Cl contained in a test \ntube. The gas evolved was passed through lime water. What change \nwould be observed in lime water? Write chemical reactions for both the \nchanges observed.  \n13. Astha  has been collecting silver coins and Co pper coins. One day she \nobserved a  black coating on silver coins and a green coating on Co pper \ncoins. Which chemical phenomenon is responsible for these coatings? \nWrite the chemical name of black and green coatings  \n14.  Identify the type of chemical reaction  \n(i)  \n(ii)  \n15. A student took 2 -3 g o f a substance X in a glass beaker & poured water \nover it slowly. He observed bubbles along with hissing noise.",
  "Identify the type of chemical reaction  \n(i)  \n(ii)  \n15. A student took 2 -3 g o f a substance X in a glass beaker & poured water \nover it slowly. He observed bubbles along with hissing noise. The \nbeaker becomes quite hot. Identify X. What type of reaction is it?",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\nover it slowly. He observed bubbles along with hissing noise. The \nbeaker becomes quite hot. Identify X. What type of reaction is it?  \n16. A substance X used for coating iron articles is added to a blue sol ution \nof a reddish brown metal. T he colour  of the solution gets discharged \nIdentify X and Y & also the type of reaction.  \n17. A solution of a substance \u2018X\u2019 is used for white washing  \n         i. Name the substance \u2018X\u2019 and writes its formula.  \n         ii. Write the reaction of the substance \u2018X\u2019 named in (i) above with water  \n18. A shiny brown coloured element \u2018X\u2019 on heating in air becomes black in \ncolour. Name the element \u2018X\u2019 and the black coloured compound formed.  \n19. An aqueous solution of metal nitrate P reacts with sodium  bromide \nsolution to form yellow ppt of compound Q which is used in \nphotography. Q on exposure to sunlight undergoes decomposition \nreaction to form metal present in P along with reddish brown gas.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\nsolution to form yellow ppt of compound Q which is used in \nphotography. Q on exposure to sunlight undergoes decomposition \nreaction to form metal present in P along with reddish brown gas. \nIdentify P &Q. Write the chemical reaction & type of chemic al reaction.  \n20. A reddish brown vessel developed a green coloured  solid X When left \nopen in air for a long time. When reacted with dil  , it forms a blue \ncoloured solution along with brisk effervescence  due to colourless & \nodourless gas Z. X decomposes to for m black coloured  oxide Y of a \nreddish brown metal along with gas Z, Identify X, Y, & Z.  \n21.  A metal is heated with dil H 2SO 4. The gas evolved is collected by the \nmethod shown in the figure: Answer the following",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-COMPETENCY BASED QUESTIONS.txt\n(a) Name the gas.  \n(b) Name the method of collection of gas.  \n(c) Is the gas soluble or insoluble in water?  \n(d) Is the gas lighter or heavier than air?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\n1 \n SALWAN PUBLIC SCHOOL , RAJENDRA  NAGAR  \nCLASS \u2013 X \nLESSON PLAN  \nCHAPTER -1: CHEMICAL REACTIONS AND EQUATIONS  \nCHAPTER -1: Science :( CHEMICAL REACTIONS AND EQUATIONS )  \nClass Transaction  \n \n \n \n(9-10 days)  PART -I \n \nTotal: 4 periods (approx. 35 min each)  \n \nSub-Topic: Introduction regarding situations of daily life -Physical and   \n                    chemical changes  \nSub-Topic: Chemical equations(writing equations)  \n \nSub-Topic: Chemical equations(writing balancing equations)  \n \nSub-Topic : Type of chemical reactions (combina tion and decomposition)  \n \nPre-requisite for the \ncourse (KNOWLEDGE)  This lesson requires:  \n\uf0b7 Basic knowledge of the situations of daily life and think what happens  \nwhen physical and chemical changes take place  \n\uf0b7 The nature and the identity of the initial substance have somewhat \nchanged.  \n\uf0b7 What  is actually meant by a chemical reaction?",
  "\uf0b7 What  is actually meant by a chemical reaction?  How do we come to \nknow that a chemical reaction has taken place?  \n \nLearning Objectives",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nLearning Objectives  \n \n Students will be able to:  \n\uf0b7 recognize  the Physical  and chemical  processes  associated  with  \nbiological  and industrial  processes  affecting  life and the \nenvironment.  \n\uf0b7 understand  chemical reaction they encounter every day.  \n\uf0b7 represent  equations  to represent  the reactions . \n\uf0b7 apply  the principles  of conservation  of mass  to balance  chemical  \nreactions   \n\uf0b7 identify the different types of chemical reaction and explain.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nTeachers ' activity  \n Introduction:  Teacher will introduce the topic by asking various questions \nfrom previous knowledge : \n\uf0b7 Analytical skills (scrutinizing an observation): To identify physical \nand chemical changes.  Example -Paper is torn or Paper is burnt, ice \nis melting or iron nail is kept exposed to moist air.  \n Evidence -based active -learning instructional strategies : \n\uf0b7 Problem solving (investigating and applying established principles \nto justify an observation)  \n 2 \n  \nExample - Activity: -Burning of a magnesium ribbon in air and collection of \nmagnesium oxide in a watch -glass.   \nConcept insight:  Always remember that magnesium being a reactive metal will \nreact with oxygen if kept in open. So, it has to be cleaned before it is burned in \nair. \nActivity: -Formation of hydrogen gas by the action of dilute hydrochloric acid on \nzinc.  \nConcept insight:  The key to this answer is to remember that metals react with",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nair. \nActivity: -Formation of hydrogen gas by the action of dilute hydrochloric acid on \nzinc.  \nConcept insight:  The key to this answer is to remember that metals react with \nhydrochloric acid to form respective metal chlorides an d liberate hydrogen gas.  \n\uf0b7 Critical thinking and collaboration (Competitive evaluation of given \ninformation)  \nExample - To make a chemical equation more informative, the physical states of \nthe reactants and products are mentioned along with their chemical form ulae \nfrom given information of different activities.  \nConcept insight:  First convert the word equation into skeletal equation with \nstate and then balance the different atoms on both sides of the equation.  \n\uf0b7 The ability to understand complex concepts (Inspect ing and  analyzing \nreasons for variation in established principles);Types of chemical \nreactions:  \nExample - Combination and decomposition reactions : Chemical reactions",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nreasons for variation in established principles);Types of chemical \nreactions:  \nExample - Combination and decomposition reactions : Chemical reactions \ninvolve the breaking and making of bonds between atoms to produce new \nsubstances and balan cing equations with the help of law of conservation of \nmass  \nConcept insight:  Remember that a chemical equation should be balanced to \nfollow the Law of conservation of mass.  \nRecapitulation  (working effectively with others):   \nExample -Discuss brain storming questions in class in group.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nLearning  Outcomes  Students will be able to know:  \n\uf0b7 A complete chemical equation which represents the reactants, \nproducts and their physical states symbolically.  \n\uf0b7 How to write the balanced chemical equation . \n\uf0b7 A combination  and d ecomposition  reactions.  \n\uf0b7 Reactions in which heat is given out along with the products are \ncalled exothermic  reactions.  \n\uf0b7 Reactions in which energy is absorbed are known as endothermic \nreactions.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nAssessment  \uf0b7 Continuously monitor student  progress by asking oral questions.  \n\uf0b7 Providing active involvement  of students in their own learning by \ngiving daily Practice Problems  in the class.  \n\uf0b7 Peer assessment  in Lab Activities  \n\uf0b7 Written test  \nSelf-Study, \uf0b7 Self-Study (Independent Practice) -The teacher  would ensure that 3 \n  Assignments , \nHomework  each student should bring NCERT Book  and tries  to be independent \nat the work  as well as be under the teacher\u2019s guidance.  \n\uf0b7 Guided practice followed by Independent Practice  ( Question \nBank):  \nOn completion of the chapter, students will be answer  the following \nrevision questions:  \nQ.1.Why should a magnesium ribbon be cleaned before burning in air?  \nQ.2. Write a balanced chemical equation with state symbols for the  \nreactions: Sodium hydroxide solution (in water) reacts with hydrochloric  \nacid so lution (in water) to produce sodium chloride solution and  water.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nreactions: Sodium hydroxide solution (in water) reacts with hydrochloric  \nacid so lution (in water) to produce sodium chloride solution and  water.  \nQ.3.Take a few zinc granules in a conical flask or a test tube and a dd dilute \nhydrochloric acid or sulphuric acid to this.  \n(a)Do you observe anything happening aroun d the zinc  granules?  \n(b)Touch the conical flask or test tube. Is there any change in  its \ntemperature?  \nQ.4.Take a small amount of calcium oxide or quick lime in a beaker , slowly \nadd water to this and touch the beaker.  \n(a)Do you feel any change in temperature?  \n(b) Write the balanced  chemical equation with physical state.  \nQ.5.Take about 2 g silver chloride in a china dish and  Place this china dish in \nsunlight for some time.  \n(a)Observe the colour of the silver chloride after some  time \n(b).Name type of the reaction.",
  "Q.5.Take about 2 g silver chloride in a china dish and  Place this china dish in \nsunlight for some time.  \n(a)Observe the colour of the silver chloride after some  time \n(b).Name type of the reaction.  \nQ.6.Take about 2 g barium hydroxide in a test tube. Add 1 g of ammonium",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN TEACHER.txt\nsunlight for some time.  \n(a)Observe the colour of the silver chloride after some  time \n(b).Name type of the reaction.  \nQ.6.Take about 2 g barium hydroxide in a test tube. Add 1 g of ammonium \nchloride and mix  with the help of a glass rod. Touch the bottom of the test \ntube with your palm.  \n(a)What do you  feel?  \n(b)Is this an exothermic or endothermic reaction?  \nHomework: The students, with the help of the teacher, will solve the \nquestions from NCERT back e xercise  in their notebook.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\n1 \n SALWAN PUBLIC SCHOOL , RAJENDRA  NAGAR  \nCLASS \u2013 X \nLESSON PLAN  \nCHAPTER -1: CHEMICAL REACTIONS AND EQUATIONS  \nCHAPTER -1: Science :( CHEMICAL REACTIONS AND EQUATIONS )  \nClass Transaction  \n \n \n \n \n(10-12 days)  PART -II",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\n(10-12 days)  PART -II \n \nTotal: 5 periods (approx. 35 min each)  \nSub-Topic: Types of chemical reactions -Combination Reaction and different \nactivities.  \nSub-Topic:  Types of chemical reactions -Decomposition Reaction and different \nactivities.  \nSub-Topic:  Types of chemical reactions -Displacement Reaction and different \nactivities.  \nSub-Topic : Type of chemical reactions \u2013Double displacement reaction and \ndifferent activities.  \nSub-Topic :- Oxidation and reduction reaction (Corrosion and  rancidity)  \nPre-requisite for the \ncourse (KNOWLEDGE)  This lesson requires:  \n\uf0b7 Knowledge of the basic properties and mechanisms  of chemical \nreactions.  \n\uf0b7 The nature and the identity of the initial substance have somewhat \nchanged.  \n\uf0b7 What  is actually meant by a chemical reaction?  How do we come to \nknow that a chemical reaction has taken place?  \n \nLearning Objectives",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nLearning Objectives  \n \n Students will be able to:  \n\uf0b7 Classify a chemical reaction as a combination, decomposition, \nsingle replacement, double replacement, exothermic or \nendothermic reaction.   \n\uf0b7 Differentiate between the types of chemical reactions.  \n\uf0b7 Predict the products of  a chemical reaction.  \n\uf0b7 Understand the different sets of conditions required such as \ntemperature, light etc  in reactions.  \n\uf0b7 Know the  effects of oxidation reactions in everyday life like \ncorrosion and rancidity.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nTeachers ' activity  \n Introduction:  Teacher will introduce the topic by performing  various \nactivities:  \nEvidence -based active -learning instructional strategies : \n\uf0b7 Problem solving (investigating and applying established principles \nto justify an observation)  Activity: -  \nExample -1-: Formation of calcium hydroxide  \nExample -2: Heating of calcium carbonate  \nExample -3: Electrolysis of water  2 \n Example -4: Reaction of iron nails with copper sulphate solution  \nExample -5: Reaction between Sodium Sulphate and Barium Chloride  \nExample -6: Reaction between Cu and O 2; CuO and H 2. \n\uf0b7 Critical thinking and collaboration (Competitive evaluation  of given \ninformation)  \nRecall Activity :   \nYou are given test tube, the solutions of lead  (II) nitrate and potassium iodide \nand are instructed to mix together in a test tube. Give answers by activity :  \n(i)What was the colour of the precipitate formed? Can you name the   \n      compound precipitated?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nand are instructed to mix together in a test tube. Give answers by activity :  \n(i)What was the colour of the precipitate formed? Can you name the   \n      compound precipitated?  \n(ii)Write the balanced chemical equation for this reaction.  \n(iii)Is this also a double displacement reaction?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\n\uf0b7 The ability to understand the effects of oxidation reactions in \neveryday life?  \nExample - Browning of cut surfaces of fruits.  Formation of metal oxide on \nmetal like iron rust -Corrosion,  Burning of crackers , Rancidity:  \n\uf0b7 Recapitulation  (working effectively with others):   \n             Example -Discuss brain storming questions in class in group.  \n \nLearning  Outcomes  Students will be able to know  \n\uf0b7 displacement and double displacement reaction.  \n\uf0b7 precipitation reactions which produce insoluble salts.  \n\uf0b7 importance of Redox reaction in ever day life.  Oxidation is the gain of \noxygen or loss of hydrogen. Reduction is the loss of oxygen or gain of \nhydrogen.  \n\uf0b7 molecular interactions and chemical reactions in the body .",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nAssessment  \uf0b7 Continuously monitor student  progress by asking oral questions.  \n\uf0b7 Providing active involvement  of students in their own learning by \ngiving daily Practice Problems  in the class.  \n\uf0b7 Peer assessment  in Lab Activities  \n\uf0b7 Written test  \nSelf-Study, \nAssignments , \nHomework  \uf0b7 Self-Study (Independent Practice) -The teacher  would ensure that \neach student should bring NCERT Book  and tries  to be independent \nat the work  as well as be under the teacher\u2019s guidance.  \n\uf0b7 Guided practice followed by Independent Practice  ( Question \nBank):  \nOn completion  of the chapter, students will be answer  the following \nrevision questions:  \nQ.1.Give some examples of combination and decomposition reactions.  \nQ.2. What happens when Ferrous sulphate crystal is heated? Write the \nequations also.  \nQ.3.Dissolve 0.5 gram silver nitrate 10 ml of water in a test tube and place a 3 \n  Copper wire in a test tube.  \nExplain your observation.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nequations also.  \nQ.3.Dissolve 0.5 gram silver nitrate 10 ml of water in a test tube and place a 3 \n  Copper wire in a test tube.  \nExplain your observation.  \nQ.4. What is the difference between displacement and double displacement \nreactions? Write equations for these reactions.  \nQ.5.Take about 2 g silver bromide  in a china dish and  Place this china dish in \nsunlight for some time.  \n(a)Observe the colour of the silver bromide  after some  time \n(b).Name type of the reaction.  \nQ.6.An iron knife kept dipped in a blue copper sulphate  solution turns the \nblue solution light green. Why?  \nHomework: The students, with the help of the teacher, will solve the \nquestions from NCERT back e xercise  in their notebook.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-5 MARKS.txt\nLong Answer Type Questions [ 5 Marks ]  \n1. (a) Define a balanced chemical equation. Why should an equation be \nbalanced?  \n(b) Write the balanced chemical equation for the following reaction:  \n(i) Phosphorus burns in presence of chlorine to form phosphorus penta \nchloride.  \n(ii) Burning of natural gas.  \n(iii) The process of respiration.  \n2. (a) Explain two ways by which food industries prevent rancidity.  \n(b) Discuss the importance of decomposition reacti on in metal industry with \nthree points.  \n3. (a) Write one example for each of decomposion reaction carried out with help \nof \n(i) Electricity (ii) Heat (iii) Light  \n(b) Which of the following statements is correct and why copper can displace \nsilver from silver ni trate and silver can displace copper from copper sulphate \nsolution.  \n4. What happens when a piece of  \n(a) Zinc metal is added to copper suphste solution?  \n(b) Aluminium metal is added to dilute hydrochloric acid?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-5 MARKS.txt\nsolution.  \n4. What happens when a piece of  \n(a) Zinc metal is added to copper suphste solution?  \n(b) Aluminium metal is added to dilute hydrochloric acid?  \n(c) Silver metal is added to copper sulphate solution?  \nAlso write the balanced chemical equation if the reaction occurs.  \n5. On heating blue coloured powder of copper (II) nitrate in a boiling tube , \ncopper oxide (black), oxygen gas and a brown gas X is formed.  \n(a) Write a balanced chemical equation of the reaction  \n(b) Identif y the brown gas x evolved.  \n(c) Identify the type of reaction  \n(d) What could be the pH range of aqueous solution of the gas x?  \n6. On adding a drop of barium chloride solution to an aqueous solution of \nsodium sulphate, white precipitate is obtained.  \n(a) Write the balanced chemical equation of the reaction involved.  \n(b) What other name can be given to this precipitation reaction?  \n(c) On adding diu te hydrochloric acid to the reaction mixture, white precipitate \ndisappears. Why?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-5 MARKS.txt\n(b) What other name can be given to this precipitation reaction?  \n(c) On adding diu te hydrochloric acid to the reaction mixture, white precipitate \ndisappears. Why?  \n7. You are provided with two containers made up of copper and aluminium. You \nare aso provided with solutions of dilute HCl, dilute HNO 3, ZnCl 2 and H 2O. In \nwhich of the above cont ainers of these solutions can be kept?",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nLESSON PLAN  \nClass: 10              Chapter: 1 ( Chemical Reactions and Equations )",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nTopics to be covered  Chemical reactions,  writing chemical equations,  Balancing \nchemical equations, types of chemical reactions -\ncombination reactions, decomposition reactions,  \ndisplacement reactions,  double displacement reactions,  \nneutralization reactions , precipitation reactions,  redox \nreactions  \nPrevious Knowledge  \u2022 Students know differences between physical \nchange and chemical change  \n\u2022 Studied the symbols of elements and chemical \nformulae of molecules.  \n\u2022 Also studied law of conservation of mass.  \nLearning Objectives  \u2022 To understand the chemical reactions in daily life  \n\u2022 Able to write the chemical equations from the \nstatements  \n\u2022 Understand how to balance chemical reactions  \n\u2022 Study different types of chemical reactions  \n\u2022 Define the terms reactants, products, precipitate, \nneutralization etc.  \nLearning Experiences  \u2022 In combination reactions two or more substances \ncombine to form a single compound . \n\u2022 In decomposition reactions a single compound",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nneutralization etc.  \nLearning Experiences  \u2022 In combination reactions two or more substances \ncombine to form a single compound . \n\u2022 In decomposition reactions a single compound \nbreaks down into two or more substances.  \n\u2022 Displacement reactions are the reactions in which a \nmore active element displace a less active element \nfrom its solution.  \n\u2022 In double displacement reactions ions are \nexchanged  between two compounds.  \n\u2022 REDuction + Oxidation = REDOX reaction  \nResources  NCERT book  \nReference book \u2013Prdeeps Publications  \nYou tube ,education channels",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-LESSON PLAN FOR TEACHERS.txt\nTeaching Aids  Usage of ICT( power point) multimedia., Lab activities( \nvirtual lab also)  \n \nProcedure  Class starts with the introduction  \nThe topics are presenting with power point , audiovisual \naids, virtual lab and lab activities  \nAt the end homework and assignments are given  \n \nAssessment Methods  Oral questioning , class tests and monthly tests",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-IMPORTANT NOTES.txt\nFocus Points  \n1.Chemical Reaction:  During chemical reactions, the chemical composition of \nsubstances changes or new substances are formed.  \n2. Chemical Equation:  Chemical reactions can be written in chemical equation form \nwhich should always be balanced.  \n3. Types of Chemical Reactions:  \nCombination reaction:  A single product is formed from two or more reactants.  \n2Mg + O 2 \u2192 2MgO  \nDecomposition reaction:  A single reactant breaks down to yield two or more \nproducts.  \n\uf0b7 Thermal decomposition:  2Pb(NO 2)2 \u2192 2PbO + 4NO 2 + O 2 \n\uf0b7 Electrolysis:  2H20 \u2192 2H 2 + O 2 \n\uf0b7 Photochemical reaction:  2AgBr \u2192 2Ag + Br 2 \nDisplacement reaction:  One element is displaced by another element.  \nZn + CuSO 4 \u2192 ZnSO 4 + Cu  \nDouble displacement reaction:  Exchange of ions between reactants.",
  "Zn + CuSO 4 \u2192 ZnSO 4 + Cu  \nDouble displacement reaction:  Exchange of ions between reactants.  \nAgNO 3 + NaCl \u2192 AgCl + NaNO 3 \nRedox reaction:  Both oxidation and reduction take place simultaneously.  \nCuO + H 2 \u2192 Cu + H 2O",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-IMPORTANT NOTES.txt\nDouble displacement reaction:  Exchange of ions between reactants.  \nAgNO 3 + NaCl \u2192 AgCl + NaNO 3 \nRedox reaction:  Both oxidation and reduction take place simultaneously.  \nCuO + H 2 \u2192 Cu + H 2O \nExothermic reaction:  A chemical reaction in which heat energy is evolved.  \nC + O 2 \u2192 CO 2 (g) + heat  \nEndothermic reaction:  A chemical reaction in which heat en ergy is absorbed.  \nZnCO 3 + Heat \u2192 ZnO + CO 2 \nRedox reaction:  Chemical reaction in which both oxidation and reduction take place \nsimultaneously.  \n4. Oxidation:  Reaction that involves the gain of oxygen or loss of hydrogen.  5. Reduction:  Reaction that shows the  loss of oxygen or gain of hydrogen.  \n                             ZnO + C \u2192 Zn + CO  \n        ZnO is reduced to Zn \u2014reduction.  \n         C is oxidized to CO \u2014Oxidation.  \n6.",
  "5. Reduction:  Reaction that shows the  loss of oxygen or gain of hydrogen.  \n                             ZnO + C \u2192 Zn + CO  \n        ZnO is reduced to Zn \u2014reduction.  \n         C is oxidized to CO \u2014Oxidation.  \n6. Effects of Oxidation Reactions in Our Daily Life:  \n\uf0b7 Corrosion:  It is an undesirable change  that occurs in metals when they are \nattacked by moisture, air, acids and bases.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS-IMPORTANT NOTES.txt\n6. Effects of Oxidation Reactions in Our Daily Life:  \n\uf0b7 Corrosion:  It is an undesirable change  that occurs in metals when they are \nattacked by moisture, air, acids and bases.  \nExample, Corrosion (rusting) of Iron: Fe 2O3. nH 2O (Hydrated iron oxide)  \n\uf0b7 Rancidity:  Undesirable change that takes place in oil containing food items \ndue to the oxidation of fat ty acids.  \nPreventive methods of rancidity: Adding antioxidants to the food materials, \nstoring food in the airtight container, flushing out air with nitrogen gas and \nrefrigeration.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nChemical Reactions\nand Equations1 CHAPTER\nConsider the following situations of daily life and think what happens\nwhen \u2013\n\u0084milk is left at room temperature during summers.\n\u0084an iron tawa/pan/nail is left exposed to humid atmosphere.\n\u0084grapes get fermented.\n\u0084food is cooked.\n\u0084food gets digested in our body.\n\u0084we respire.\nIn all the above situations, the nature and the identity of the initialsubstance have somewhat changed. We have already learnt about physicaland chemical changes of matter in our previous classes. Whenever a chemicalchange occurs, we can say that a chemical reaction has taken place.\nYou may perhaps be wondering as to what is actually meant by a\nchemical reaction. How do we come to know that a chemical reactionhas taken place? Let us perform some activities to find the answer to\nthese questions.\nFigure 1.1\nBurning of a magnesium ribbon in air and collection of magnesiumoxide in a watch-glassActivity 1.1Activity 1.1Activity 1.1Activity 1.1Activity 1.1",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nthese questions.\nFigure 1.1\nBurning of a magnesium ribbon in air and collection of magnesiumoxide in a watch-glassActivity 1.1Activity 1.1Activity 1.1Activity 1.1Activity 1.1\nCAUTION:  This Activity needs\nthe teacher\u2019s assistance. It\nwould be better if studentswear eye protection.\n\u0084Clean a magnesium ribbonabout 2 cm long by rubbingit with sandpaper.\n\u0084Hold it with a pair of tongs.Burn it using a spirit lamp orburner and collect the ash so\nformed in a watch-glass as\nshown in Fig. 1.1. Burn  themagnesium ribbon keeping it\nas far as possible from your\neyes.\n\u0084What do you observe?",
  "1.1. Burn  themagnesium ribbon keeping it\nas far as possible from your\neyes.\n\u0084What do you observe?\n\u201cFacts are not science \u2014 as the dictionary is not literature.\u201d\nMartin H. FischerScience 2Activity 1.2Activity 1.2Activity 1.2Activity 1.2Activity 1.2\nFigure 1.2\nFormation of hydrogengas by the action ofdilute sulphuric acid onzincFrom the above three activities, we can say that any ofthe following observations helps us to determine whethera chemical reaction has taken place \u2013\n\u0084change in state\n\u0084change in colour",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084change in state\n\u0084change in colour\n\u0084evolution of a gas\n\u0084change in temperature.\nAs we observe the changes around us, we can see\nthat there is a large variety of chemical reactions taking\nplace around us. We will study about the various types\nof chemical reactions and their symbolic representationin this Chapter.Activity 1.3Activity 1.3Activity 1.3Activity 1.3Activity 1.3\n\u0084Take a few zinc granules in a conical flask or a test tube.\n\u0084Add dilute hydrochloric acid or sulphuric acid to this\n(Fig. 1.2).CAUTION:  Handle the acid with care.\n\u0084Do you observe anything happening around the zinc\ngranules?\n\u0084Touch the conical flask or test tube. Is there any change inits temperature?\u0084Take lead nitratesolution in a testtube.\n\u0084Add potassiumiodide solutionto this.\n\u0084What do youobserve?",
  "\u0084Do you observe anything happening around the zinc\ngranules?\n\u0084Touch the conical flask or test tube. Is there any change inits temperature?\u0084Take lead nitratesolution in a testtube.\n\u0084Add potassiumiodide solutionto this.\n\u0084What do youobserve?\n1.1 CHEMIC1.1 CHEMIC1.1 CHEMIC1.1 CHEMIC1.1 CHEMIC AL EQUAAL EQUAAL EQUAAL EQUAAL EQUA TIONSTIONSTIONSTIONSTIONS\nActivity 1.1 can be described as \u2013 when a magnesium ribbon is burnt in",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n1.1 CHEMIC1.1 CHEMIC1.1 CHEMIC1.1 CHEMIC1.1 CHEMIC AL EQUAAL EQUAAL EQUAAL EQUAAL EQUA TIONSTIONSTIONSTIONSTIONS\nActivity 1.1 can be described as \u2013 when a magnesium ribbon is burnt in\noxygen, it gets converted to magnesium oxide. This description of achemical reaction in a sentence form is quite long. It can be written in ashorter form. The simplest way to do this is to write it in the form of aword-equation.The word-equation for the above reaction would be \u2013\nMagnesium + Oxygen \u2192Magnesium oxide (1.1)\n            (Reactants) (Product)\nThe substances that undergo chemical change in the reaction (1.1),\nmagnesium and oxygen, are the reactants. The new substance,magnesium oxide, formed during the reaction, is the product.\nA word-equation shows change of reactants to products through an",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nmagnesium and oxygen, are the reactants. The new substance,magnesium oxide, formed during the reaction, is the product.\nA word-equation shows change of reactants to products through an\narrow placed between them. The reactants are written on the left-handside (LHS) with a plus sign (+) between them. Similarly, products arewritten on the right-hand side (RHS) with a plus sign (+) between them.The arrowhead points towards the products, and shows the direction ofthe reaction.You must have observed that magnesium ribbon burns with a\ndazzling white flame and changes into a white powder. This powder is\nmagnesium oxide. It is formed due to the reaction between magnesiumand oxygen present in the air.Chemical Reactions and Equations 31.1.1 Writing a Chemical Equation\nIs there any other shorter way for representing chemical equations?\nChemical equations can be made more concise and useful if we use\nchemical formulae instead of words. A chemical equation represents a",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nChemical equations can be made more concise and useful if we use\nchemical formulae instead of words. A chemical equation represents a\nchemical reaction. If you recall formulae of magnesium, oxygen andmagnesium oxide, the above word-equation can be written as \u2013\nMg + O\n2  \u2192  MgO (1.2)\nCount and compare the number of atoms of each element on the\nLHS and RHS of the arrow. Is the number of atoms of each element the\nsame on both the sides? If not, then the equation is unbalanced because\nthe mass is not the same on both sides of the equation. Such a chemicalequation is a skeletal chemical equation for a reaction. Equation (1.2) is\na skeletal chemical equation for the burning of magnesium in air.\n1.1.2 Balanced Chemical Equations\nRecall the law of conservation of mass that you studied in Class IX; mass\ncan neither be created nor destroyed in a chemical reaction. That is, thetotal mass of the elements present in the products of a chemical reaction",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\ncan neither be created nor destroyed in a chemical reaction. That is, thetotal mass of the elements present in the products of a chemical reaction\nhas to be equal to the total mass of the elements present in the reactants.\nIn other words, the number of atoms of each element remains the\nsame, before and after a chemical reaction. Hence, we need to balance a\nskeletal chemical equation. Is the chemical Eq. (1.2) balanced? Let us\nlearn about balancing a chemical equation step by step.\nThe word-equation for Activity 1.3 may be represented as \u2013\nZinc + Sulphuric acid  \u2192  Zinc sulphate + Hydrogen\nThe above word-equation may be represented by the following\nchemical equation \u2013\nZn + H\n2SO4 \u2192 ZnSO4 + H2(1.3)\nLet us examine the number of atoms of different elements on both\nsides of the arrow.",
  "Element Number of atoms in Number of atoms\nreactants (LHS) in products (RHS)\nZn 1 1\nH2 2\nS1 1\nO4 4\nAs the number of atoms of each element is the same on both sides of",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nsides of the arrow.\nElement Number of atoms in Number of atoms\nreactants (LHS) in products (RHS)\nZn 1 1\nH2 2\nS1 1\nO4 4\nAs the number of atoms of each element is the same on both sides of\nthe arrow, Eq. (1.3) is a balanced chemical equation.\nLet us try to balance the following chemical equation \u2013\nFe + H2O \u2192 Fe3O4 + H2(1.4)Science 4Step I:  To balance a chemical equation, first draw boxes around each\nformula. Do not change anything inside the boxes while balancing theequation.\nFe   +   H\n2O   \u2192   Fe3O4   +   H2(1.5)\nStep II:  List the number of atoms of different elements present in the\nunbalanced equation (1.5).",
  "Do not change anything inside the boxes while balancing theequation.\nFe   +   H\n2O   \u2192   Fe3O4   +   H2(1.5)\nStep II:  List the number of atoms of different elements present in the\nunbalanced equation (1.5).\nElement Number of atoms Number of atoms\nin reactants (LHS) in products (RHS)\nFe 1 3\nH2 2\nO1 4\nTo equalise the number of atoms, it must be remembered that we\ncannot alter the formulae of the compounds or elements involved in thereactions. For example, to balance oxygen atoms we can put coefficient\u20184\u2019 as 4 H\n2O and not H2O4 or (H2O)4. Now the partly balanced equation\nbecomes \u2013",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n2O and not H2O4 or (H2O)4. Now the partly balanced equation\nbecomes \u2013\nFe   +   4 H2O   \u2192   Fe3O4   +   H2\nStep IV:  Fe and H atoms are still not balanced. Pick any of these elements\nto proceed further. Let us balance hydrogen atoms in the partly balancedequation.\nTo equalise the number of H atoms, make the number of molecules\nof hydrogen as four on the RHS.Step III:  It is often convenient to start balancing with the compound\nthat contains the maximum number of atoms. It may be a reactant or aproduct. In that compound, select the element which has the maximumnumber of atoms. Using these criteria, we select Fe\n3O4 and the element\noxygen in it. There are four oxygen atoms on the RHS and only one onthe LHS.",
  "It may be a reactant or aproduct. In that compound, select the element which has the maximumnumber of atoms. Using these criteria, we select Fe\n3O4 and the element\noxygen in it. There are four oxygen atoms on the RHS and only one onthe LHS.\nTo balance the oxygen atoms \u2013\nThe equation would be \u2013\n  Fe   +   4   H2O   \u2192   Fe3O4   +   4 H2Atoms of In reactants In products\noxygen\n(i) Initial 1 (in H2O) 4 (in Fe3O4)\n(ii) To balance 1\u00d74 4\nAtoms of In reactants In products\nhydrogen\n(i) Initial 8 (in 4 H2O) 2 (in H2)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\noxygen\n(i) Initial 1 (in H2O) 4 (in Fe3O4)\n(ii) To balance 1\u00d74 4\nAtoms of In reactants In products\nhydrogen\n(i) Initial 8 (in 4 H2O) 2 (in H2)\n(ii) To balance 8 2 \u00d7 4(1.6)\n(partly balanced equation)\n(1.7)\n(partly balanced equation)Chemical Reactions and Equations 5To equalise Fe, we take three atoms of Fe on the LHS.\n3   Fe   +   4   H2O   \u2192   Fe3O4   +   4   H2(1.8)\nStep VI:  Finally, to check the correctness of the balanced equation, we\ncount atoms of each element on both sides of the equation.\n3Fe + 4H2O \u2192 Fe3O4 + 4H2\nThe numbers of atoms of elements on both sides of Eq. (1.9) are\nequal. This equation is now balanced.",
  "3Fe + 4H2O \u2192 Fe3O4 + 4H2\nThe numbers of atoms of elements on both sides of Eq. (1.9) are\nequal. This equation is now balanced. This method of balancing chemicalequations is called hit-and-trial method as we make trials to balancethe equation by using the smallest whole number coefficient.\nStep VII: Writing Symbols of Physical States   Carefully examine",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nStep VII: Writing Symbols of Physical States   Carefully examine\nthe above balanced Eq. (1.9). Does this equation tell us anything aboutthe physical state of each reactant and product? No information hasbeen given in this equation about their physical states.\nTo make a chemical equation more informative, the physical states\nof the reactants and products are mentioned along with their chemicalformulae. The gaseous, liquid, aqueous and solid states of reactantsand products are represented by the notations (g), (l), (aq) and (s),respectively. The word aqueous (aq) is written if the reactant or productis present as a solution in water.\nThe balanced Eq. (1.9) becomes\n3Fe(s) + 4H\n2O(g)  \u2192 Fe3O4(s) + 4H2(g) (1.10)\nNote that the symbol (g) is used with H2O to indicate that in this\nreaction water is used in the form of steam.",
  "Usually physical states are not included in a chemical equation unless\nit is necessary to specify them.\nSometimes the reaction conditions, such as temperature, pressure,",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nUsually physical states are not included in a chemical equation unless\nit is necessary to specify them.\nSometimes the reaction conditions, such as temperature, pressure,\ncatalyst, etc., for the reaction are indicated above and/or below the arrowin the equation. For example \u2013\nCO(g) + 2H (g)2340atmCH OH(l)3 \uf8e7\u2192\uf8e7\uf8e7\uf8e7\uf8e7 (1.11)\n6CO (aq) 6H O(l) C H O (aq) 6O22 6 1 2 62 ++Sunlight\nChlorophyll\uf8e7\u2192\uf8e7\uf8e7\uf8e7\uf8e7\uf8e7 \uf8e7 ((aq) (1.12)\n        (Glucose)\nUsing these steps, can you balance Eq. (1.2) given in the text earlier?Step V:  Examine the above equation and pick up the third element which\nis not balanced. You find that only one element is left to be balanced,that is, iron.",
  "(1.2) given in the text earlier?Step V:  Examine the above equation and pick up the third element which\nis not balanced. You find that only one element is left to be balanced,that is, iron.\nAtoms of In reactants In products\niron\n(i) Initial 1 (in Fe) 3 (in Fe3O4)\n(ii) To balance 1\u00d73 3\n(1.9)\n(balanced equation)Science 61.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC AL REAAL REAAL REAAL REAAL REA CTIONSCTIONSCTIONSCTIONSCTIONS",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n(1.9)\n(balanced equation)Science 61.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC1.2 TYPES OF CHEMIC AL REAAL REAAL REAAL REAAL REA CTIONSCTIONSCTIONSCTIONSCTIONS\nWe have learnt in Class IX that during a chemical reaction atoms of one\nelement do not change into those of another element. Nor do atoms\ndisappear from the mixture or appear from elsewhere. Actually, chemicalreactions involve the breaking and making of bonds between atoms to\nproduce new substances. You will study about types of bonds formed\nbetween atoms in Chapters 3 and 4.\n1.2.1 Combination Reaction\nActivity 1.4Activity 1.4Activity 1.4Activity 1.4Activity 1.4\n\u0084Take a small amount of calcium oxide\nor quick lime in a beaker.\n\u0084Slowly add water to this.\n\u0084Touch the beaker as shown in Fig. 1.3.",
  "\u0084Slowly add water to this.\n\u0084Touch the beaker as shown in Fig. 1.3.\n\u0084Do you feel any change in temperature?\nFigure 1.3\nFormation of slakedlime by the reaction ofcalcium oxide withwater\nCalcium oxide reacts vigorously with water to produce slaked lime",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084Do you feel any change in temperature?\nFigure 1.3\nFormation of slakedlime by the reaction ofcalcium oxide withwater\nCalcium oxide reacts vigorously with water to produce slaked lime\n(calcium hydroxide) releasing a large amount of heat.\nCaO(s) + H2O(l)  \u2192 Ca(OH)2(aq) (1.13)\n(Quick lime)   (Slaked lime)\nIn this reaction, calcium oxide and water combine to form a single\nproduct, calcium hydroxide. Such a reaction in which a single productis formed from two or more reactants is known as a combination reaction.QUESTIONSQUESTIONSQUESTIONSQUESTIONSQUESTIONS\n1. Why should a magnesium ribbon be cleaned before burning in air?\n2. Write the balanced equation for the following chemical reactions.\n(i) Hydrogen + Chlorine \u2192 Hydrogen chloride\n(ii)Barium chloride + Aluminium sulphate \u2192  Barium sulphate +\n     Aluminium chloride\n(iii)Sodium + Water  \u2192 Sodium hydroxide + Hydrogen\n3.",
  "Write the balanced equation for the following chemical reactions.\n(i) Hydrogen + Chlorine \u2192 Hydrogen chloride\n(ii)Barium chloride + Aluminium sulphate \u2192  Barium sulphate +\n     Aluminium chloride\n(iii)Sodium + Water  \u2192 Sodium hydroxide + Hydrogen\n3. Write a balanced chemical equation with state symbols for the\nfollowing reactions.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nAluminium chloride\n(iii)Sodium + Water  \u2192 Sodium hydroxide + Hydrogen\n3. Write a balanced chemical equation with state symbols for the\nfollowing reactions.\n(i) Solutions of barium chloride and sodium sulphate in water react\nto give insoluble barium sulphate and the solution of sodiumchloride.\n(ii) Sodium hydroxide solution (in water) reacts with hydrochloric\nacid solution (in water) to produce sodium chloride solution andwater.?Chemical Reactions and Equations 7Let us discuss some more examples of combination reactions.\n(i) Burning of coal\nC(s) + O2(g)  \u2192 CO2(g) (1.15)\n(ii) Formation of water from H2(g) and O2(g)\n2H2(g) + O2(g) \u2192 2H2O(l) (1.16)\nIn simple language we can say that when two or more substances\n(elements or compounds) combine to form a single product, the reactionsare called combination reactions.\nIn Activity 1.4, we also observed that a large amount of heat is evolved.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n(elements or compounds) combine to form a single product, the reactionsare called combination reactions.\nIn Activity 1.4, we also observed that a large amount of heat is evolved.\nThis makes the reaction mixture warm. Reactions in which heat isreleased along with the formation of products are called exothermicchemical reactions.\nOther examples of exothermic reactions are \u2013(i) Burning of natural gas\nCH\n4(g) + 2O2 (g) \u2192 CO2 (g) + 2H2O (g) (1.17)\n(ii) Do you know that respiration is an exothermic process?\nWe all know that we need energy to stay alive. We get this energy\nfrom the food we eat. During digestion, food is broken down into simplersubstances. For example, rice, potatoes and bread containcarbohydrates. These carbohydrates are broken down to form glucose.This glucose combines with oxygen in the cells of our body and providesenergy. The special name of this reaction is respiration, the process ofwhich you will study in Chapter 6.\nC",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nC\n6H12O6(aq) + 6O2(aq) \u2192 6CO2(aq) + 6H2O(l) + energy (1.18)\n(Glucose)\n(iii) The decomposition of vegetable matter into compost is also an\nexample of an exothermic reaction.\nIdentify the type of the reaction taking place in Activity 1.1, where\nheat is given out along with the formation of a single product.\nDo You Know?A solution of slaked lime produced by the reaction 1.13 is used for white washing\nwalls. Calcium hydroxide reacts slowly with the carbon dioxide in air to form a thin\nlayer of calcium carbonate on the walls. Calcium carbonate is  formed after two to\nthree days of white washing and gives a shiny finish to the walls. It is interesting tonote that the chemical formula for marble is also CaCO\n3.",
  "Calcium carbonate is  formed after two to\nthree days of white washing and gives a shiny finish to the walls. It is interesting tonote that the chemical formula for marble is also CaCO\n3.\nCa(OH)2(aq) + CO2(g) \u2192CaCO3(s) + H2O(l) (1.14)\n(Calcium (Calcium\nhydroxide) carbonate)Science 8Figure 1.5\nHeating of lead nitrate andemission of nitrogen dioxide\nFigure 1.4Correct way of heatingthe boiling tubecontaining crystalsof ferrous sulphateand of smelling theodour",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nHeating of lead nitrate andemission of nitrogen dioxide\nFigure 1.4Correct way of heatingthe boiling tubecontaining crystalsof ferrous sulphateand of smelling theodour\nActivity 1.6Activity 1.6Activity 1.6Activity 1.6Activity 1.6\n\u0084Take about 2 g lead nitrate powder in a boiling\ntube.\n\u0084Hold the boiling tube with a pair of tongs andheat it over a flame, as shown in Fig. 1.5.\n\u0084What do you observe? Note down the change,if any.\nYou will observe the emission of brown fumes.\nThese fumes are of nitrogen dioxide (NO2). The\nreaction that takes place is \u2013Activity 1.5Activity 1.5Activity 1.5Activity 1.5Activity 1.5\n\u0084Take about 2 g ferrous sulphate crystals\nin a dry boiling tube.\n\u0084Note the colour of the ferrous sulphatecrystals.",
  "\u0084Note the colour of the ferrous sulphatecrystals.\n\u0084Heat the boiling tube over the  flame  ofa burner or spirit lamp as shown inFig. 1.4.\n\u0084Observe the colour of the crystals afterheating.\nHave you noticed that the green colour of the ferrous sulphate crystals",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084Observe the colour of the crystals afterheating.\nHave you noticed that the green colour of the ferrous sulphate crystals\nhas changed? You can also smell the characteristic odour of burningsulphur.\n2FeSO\n4(s) Heat\uf8e7\u2192\uf8e7\uf8e7\uf8e7  Fe2O3(s)  +  SO2(g)  + SO3(g) (1.19)\n(Ferrous sulphate)   (Ferric oxide)\nIn this reaction you can observe that a single reactant breaks down\nto give simpler products. This is a decomposition reaction. Ferroussulphate crystals (FeSO\n4, 7H2O) lose water when heated and the colour\nof the crystals changes. It then decomposes to ferric oxide (Fe2O3),\nsulphur dioxide (SO2) and sulphur trioxide (SO3). Ferric oxide is a solid,\nwhile SO2 and SO3 are gases.\nDecomposition of calcium carbonate to calcium oxide and carbon",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nsulphur dioxide (SO2) and sulphur trioxide (SO3). Ferric oxide is a solid,\nwhile SO2 and SO3 are gases.\nDecomposition of calcium carbonate to calcium oxide and carbon\ndioxide on heating is an important decomposition reaction used invarious industries. Calcium oxide is called lime or quick lime. It hasmany uses \u2013 one is in the manufacture of cement. When a decompositionreaction is carried out by heating, it is called thermal decomposition.",
  "Calcium oxide is called lime or quick lime. It hasmany uses \u2013 one is in the manufacture of cement. When a decompositionreaction is carried out by heating, it is called thermal decomposition.\nCaCO\n3(s) Heat\uf8e7\u2192\uf8e7\uf8e7\uf8e7  CaO(s)    +   CO2(g) (1.20)\n(Limestone)    (Quick lime)\nAnother example of a thermal decomposition reaction is given\nin Activity 1.6.1.2.2 Decomposition ReactionChemical Reactions and Equations 9Activity 1.7Activity 1.7Activity 1.7Activity 1.7Activity 1.7\nActivity 1.8Activity 1.8Activity 1.8Activity 1.8Activity 1.8\n\u0084Take about 2 g silver chloride in a china dish.\n\u0084What is its colour?\n\u0084Place this china dish in sunlight for some time\n(Fig. 1.7).\n\u0084Observe the colour of the silver chloride after sometime.\nFigure 1.7",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084What is its colour?\n\u0084Place this china dish in sunlight for some time\n(Fig. 1.7).\n\u0084Observe the colour of the silver chloride after sometime.\nFigure 1.7\nSilver chloride turns greyin sunlight to form silvermetalYou will see that white silver chloride turns grey in sunlight. This is\ndue to the decomposition of silver chloride into silver and chlorine bylight.\n2AgCl(s) \nSunlight\uf8e7\u2192\uf8e7\uf8e7\uf8e7\uf8e7 2Ag(s) + Cl2(g) (1.22)\u0084Take a plastic mug. Drill two holes at its\nbase and fit rubber stoppers in these holes.Insert carbon electrodes in these rubberstoppers as shown in Fig. 1.6.\n\u0084Connect these electrodes to a 6 voltbattery.\n\u0084Fill the mug with water such that theelectrodes are immersed. Add a few dropsof dilute sulphuric acid to the water.\n\u0084Take two test tubes filled with water andinvert them over the two carbon electrodes.",
  "\u0084Connect these electrodes to a 6 voltbattery.\n\u0084Fill the mug with water such that theelectrodes are immersed. Add a few dropsof dilute sulphuric acid to the water.\n\u0084Take two test tubes filled with water andinvert them over the two carbon electrodes.\n\u0084Switch on the current and leave theapparatus undisturbed for some time.\n\u0084You will observe the formation of bubblesat both the electrodes. These bubbles displace water in thetest tubes.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084Switch on the current and leave theapparatus undisturbed for some time.\n\u0084You will observe the formation of bubblesat both the electrodes. These bubbles displace water in thetest tubes.\n\u0084Is the volume of the gas collected the same in both the test tubes?\n\u0084Once the test tubes are filled with the respective gases, remove\nthem carefully.\n\u0084Test these gases one by one by bringing a burning candle close\nto the mouth of the test tubes.\nCAUTION:  This step must be performed carefully by the teacher.\n\u0084What happens in each case?",
  "\u0084Once the test tubes are filled with the respective gases, remove\nthem carefully.\n\u0084Test these gases one by one by bringing a burning candle close\nto the mouth of the test tubes.\nCAUTION:  This step must be performed carefully by the teacher.\n\u0084What happens in each case?\n\u0084Which gas is present in each test tube?Figure 1.6\nElectrolysis of water2Pb(NO3)2(s) Heat\uf8e7\u2192\uf8e7\uf8e7\uf8e7 2PbO(s) + 4NO2(g)  +  O2(g) (1.21)\n(Lead nitrate)       (Lead oxide) (Nitrogen (Oxygen)\ndioxide)\nLet us perform some more decomposition reactions as given in\nActivities 1.7 and 1.8.Science 10\nFigure 1.8\n(a) Iron nails dipped in copper sulphate solution?QUESTIONSQUESTIONSQUESTIONSQUESTIONSQUESTIONS\n1. A solution of a substance \u2018X\u2019 is used for white washing.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nFigure 1.8\n(a) Iron nails dipped in copper sulphate solution?QUESTIONSQUESTIONSQUESTIONSQUESTIONSQUESTIONS\n1. A solution of a substance \u2018X\u2019 is used for white washing.\n(i) Name the substance \u2018X\u2019 and write its formula.\n(ii) W rite the r eaction of the substance \u2018X\u2019 named in (i) above with\nwater.\n2. Why is the amount of gas collected in one of the test tubes in Activity\n1.7 double of the amount collected in the other? Name this gas.\n1.2.3  Displacement Reaction\nActivity 1.9Activity 1.9Activity 1.9Activity 1.9Activity 1.9\n\u0084Take three iron nails and clean them by\nrubbing with sand paper.\n\u0084Take two test tubes marked as (A) and(B). In each test tube, take about 10 mLcopper sulphate solution.",
  "\u0084Take two test tubes marked as (A) and(B). In each test tube, take about 10 mLcopper sulphate solution.\n\u0084Tie two iron nails with a thread andimmerse them carefully in the coppersulphate solution in test tube B forabout 20 minutes [Fig. 1.8 (a)]. Keep oneiron nail aside for comparison.\n\u0084After 20 minutes, take out the iron nailsfrom the copper sulphate solution.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084After 20 minutes, take out the iron nailsfrom the copper sulphate solution.\n\u0084Compare the intensity of the blue colourof copper sulphate solutions in test tubes(A) and (B), [Fig. 1.8 (b)].\n\u0084Also, compare the colour of the iron nailsdipped in the copper sulphate solutionwith the one kept aside [Fig. 1.8 (b)].Take about 2 g barium hydroxide in a test tube. Add 1 g of ammonium chloride and mixwith the help of a glass rod. Touch the bottom of the test tube with your palm. What do youfeel? Is this an exothermic or endothermic reaction?Carry out the following ActivitySilver bromide also behaves in the same way.\n2AgBr(s)Sunlight\uf8e7\u2192\uf8e7\uf8e7\uf8e7\uf8e7 2Ag(s) + Br2(g) (1.23)\nThe above reactions are used in black and white photography.\nWhat form of energy is causing these decomposition reactions?",
  "2AgBr(s)Sunlight\uf8e7\u2192\uf8e7\uf8e7\uf8e7\uf8e7 2Ag(s) + Br2(g) (1.23)\nThe above reactions are used in black and white photography.\nWhat form of energy is causing these decomposition reactions?\nWe have seen that the decomposition reactions require energy either\nin the form of heat, light or electricity for breaking down the reactants.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nWe have seen that the decomposition reactions require energy either\nin the form of heat, light or electricity for breaking down the reactants.\nReactions in which energy is absorbed are known as endothermicreactions.Chemical Reactions and Equations 11Why does the iron nail become brownish in colour and the blue colour\nof copper sulphate solution fade?\nThe following chemical reaction takes place in this Activity\u2013\nFe(s) + CuSO4(aq) \u2192 FeSO4(aq)    +   Cu(s) (1.24)\n        (Copper sulphate) (Iron sulphate)\nIn this reaction, iron has displaced or removed another element,\ncopper, from copper sulphate solution. This reaction is known asdisplacement reaction.",
  "This reaction is known asdisplacement reaction.\nOther examples of displacement reactions are\nZn(s) + CuSO\n4(aq) \u2192 ZnSO4(aq)   +     Cu(s) (1.25)\n     (Copper sulphate) (Zinc sulphate)\nPb(s) + CuCl2(aq) \u2192 PbCl2(aq)     +     Cu(s) (1.26)\n      (Copper chloride) (Lead chloride)\nZinc and lead are more reactive elements than copper. They displace\ncopper from its compounds.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nPb(s) + CuCl2(aq) \u2192 PbCl2(aq)     +     Cu(s) (1.26)\n      (Copper chloride) (Lead chloride)\nZinc and lead are more reactive elements than copper. They displace\ncopper from its compounds.\n1.2.4 Double Displacement Reaction\nActivity 1.10Activity 1.10Activity 1.10Activity 1.10Activity 1.10\n\u0084Take about 3 mL of sodium sulphate\nsolution in a test tube.\n\u0084In another test tube, take about 3 mL ofbarium chloride solution.\n\u0084Mix the two solutions (Fig. 1.9).\n\u0084What do you observe?\nFigure 1.9Formation of bariumsulphate and sodiumchlorideYou will observe that a white substance, which is\ninsoluble in water, is formed. This insoluble substanceformed is known as a precipitate. Any reaction thatproduces a precipitate can be called a precipitation reaction.",
  "This insoluble substanceformed is known as a precipitate. Any reaction thatproduces a precipitate can be called a precipitation reaction.\nNa\n2SO4(aq) + BaCl2(aq) \u2192 BaSO4(s) + 2NaCl(aq) (1.27)\n(Sodium (Barium (Barium (Sodium",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nNa\n2SO4(aq) + BaCl2(aq) \u2192 BaSO4(s) + 2NaCl(aq) (1.27)\n(Sodium (Barium (Barium (Sodium\nsulphate) chloride) sulphate) chloride)Figure 1.8 (b) Iron nails and copper sulphate solutions compared before and after the experimentScience 121.2.5 Oxidation and Reduction\nActivity 1.11Activity 1.11Activity 1.11Activity 1.11Activity 1.11\n\u0084Heat a china dish containing about 1 g\ncopper powder (Fig. 1.10).\n\u0084What do you observe?\nFigure 1.10\nOxidation of copper tocopper oxideThe surface of copper powder becomes coated with\nblack copper(II) oxide. Why has this blacksubstance formed?This is because oxygen is added to copper andcopper oxide is formed.",
  "\u0084What do you observe?\nFigure 1.10\nOxidation of copper tocopper oxideThe surface of copper powder becomes coated with\nblack copper(II) oxide. Why has this blacksubstance formed?This is because oxygen is added to copper andcopper oxide is formed.\n2Cu + O\n2  Heat\uf8e7\u2192\uf8e7\uf8e7\uf8e7 2CuO (1.28)\nIf hydrogen gas is passed over this heated material (CuO), the black\ncoating on the surface turns brown as the reverse reaction takes placeand copper is obtained.\nCuO +H Cu+H O22Heat\uf8e7\u2192\uf8e7\uf8e7 \uf8e7 (1.29)\nIf a substance gains oxygen during a reaction, it is said to be oxidised.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nCuO +H Cu+H O22Heat\uf8e7\u2192\uf8e7\uf8e7 \uf8e7 (1.29)\nIf a substance gains oxygen during a reaction, it is said to be oxidised.\nIf a substance loses oxygen during a reaction, it is said to be reduced.\nDuring this reaction (1.29), the copper(II) oxide is losing oxygen and\nis being reduced. The hydrogen is gaining oxygen and is being oxidised.In other words, one reactant gets oxidised while the other gets reducedduring a reaction. Such reactions are called oxidation-reduction reactionsor redox reactions.\n(1.30)\nSome other examples of redox reactions are:\nZnO + C \u2192+Zn CO (1.31)\nMnO HCl MnCl H O Cl22 2 242+\u2192 + + (1.32)Recall Activity 1.2 , where you have mixed the solutions of lead(II) nitrate\nand potassium iodide.(i) What was the colour of the precipitate formed? Can you name the compound\nprecipitated?",
  "(i) What was the colour of the precipitate formed? Can you name the compound\nprecipitated?\n(ii) Write the balanced chemical equation for this reaction.(iii) Is this also a double displacement reaction?What causes this? The  white precipitate of BaSO\n4 is formed by the\nreaction of 2\u2013",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n(ii) Write the balanced chemical equation for this reaction.(iii) Is this also a double displacement reaction?What causes this? The  white precipitate of BaSO\n4 is formed by the\nreaction of 2\u2013\n4SO  and Ba2+. The other product formed is sodium chloride\nwhich remains in the solution. Such reactions in which there is an\nexchange of ions between the reactants are called double displacementreactions.Chemical Reactions and Equations 13In reaction (1.31) carbon is oxidised to CO and ZnO is reduced to Zn.\nIn reaction (1.32) HCl is oxidised to Cl2 whereas MnO2 is reduced to MnCl2.\nFrom the above examples we can say that if a substance gains oxygen\nor loses hydrogen during a reaction, it is oxidised. If a substance losesoxygen or gains hydrogen during a reaction, it is reduced.\nQUESTIONSQUESTIONSQUESTIONSQUESTIONSQUESTIONS\n?1. Why does the colour of copper sulphate solution change when\nan iron nail is dipped in it?\n2. Give an example of a double displacement reaction other than",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n?1. Why does the colour of copper sulphate solution change when\nan iron nail is dipped in it?\n2. Give an example of a double displacement reaction other than\nthe one given in Activity 1.10.\n3. Identify the substances that are oxidised and the substances\nthat are reduced in the following reactions.\n(i) 4Na(s) + O2(g) \u2192 2Na2O(s)\n(ii) CuO(s) + H2(g) \u2192 Cu(s) + H2O(l)1.31.31.31.31.3HAHAHAHAHAVE YOU OBSERVED THE EFFECTS OF OVE YOU OBSERVED THE EFFECTS OF OVE YOU OBSERVED THE EFFECTS OF OVE YOU OBSERVED THE EFFECTS OF OVE YOU OBSERVED THE EFFECTS OF O XIDXIDXIDXIDXIDAAAAATIONTIONTIONTIONTION\nREAREAREAREAREACTIONS IN EVERYDCTIONS IN EVERYDCTIONS IN EVERYDCTIONS IN EVERYDCTIONS IN EVERYD AAAAAY LIFE?Y LIFE?Y LIFE?Y LIFE?Y LIFE?",
  "1.3.1 Corrosion\nYou must have observed that iron articles are shiny when new, but get\ncoated with a reddish brown powder when left for some time. This processis commonly known as rusting of iron. Some other metals also get",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\ncoated with a reddish brown powder when left for some time. This processis commonly known as rusting of iron. Some other metals also get\ntarnished in this manner. Have you noticed the colour of the coating\nformed on copper and silver? When a metal is attacked by substancesaround it such as moisture, acids, etc., it is said to corrode and this\nprocess is called corrosion. The black coating on silver and the green\ncoating on copper are other examples of corrosion.\nCorrosion causes damage to car bodies, bridges, iron railings, ships\nand to all objects made of metals, specially those of iron. Corrosion of\niron is a serious problem. Every year an enormous amount of money isspent to r eplace damaged iron. You will learn more about corrosion in\nChapter 3.\n1.3.2 Rancidity\nHave you ever tasted or smelt the fat/oil containing food materials leftfor a long time?\nWhen fats and oils are oxidised, they become rancid and their smell\nand taste change. Usually substances which prevent oxidation",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nWhen fats and oils are oxidised, they become rancid and their smell\nand taste change. Usually substances which prevent oxidation\n(antioxidants) are added to foods containing fats and oil. Keeping food\nin air tight containers helps to slow down oxidation. Do you know thatchips manufacturers usually flush bags of chips with gas such as\nnitrogen to prevent the chips from getting oxidised ?Recall Activity 1.1 , where a magnesium ribbon burns with a dazzling flame in air (oxygen)\nand changes into a white substance, magnesium oxide. Is magnesium being oxidised orreduced in this reaction?Science 14What you have learnt\n\u0084A complete chemical equation represents the reactants, products and their physical\nstates symbolically.\n\u0084A chemical equation is balanced so that the numbers of atoms of each type involvedin a chemical reaction are the same on the reactant and product sides of theequation. Equations must always be balanced.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n\u0084In a combination reaction two or more substances combine to form a new singlesubstance.\n\u0084Decomposition reactions are opposite to combination reactions. In a decompositionreaction, a single substance decomposes to give two or more substances.\n\u0084Reactions in which heat is given out along with the products are called exothermicreactions.\n\u0084Reactions in which energy is absorbed are known as endothermic reactions.\n\u0084When an element displaces another element from its compound, a displacementreaction occurs.\n\u0084Two different atoms or groups of atoms (ions) are exchanged in double displacementreactions.\n\u0084Precipitation reactions produce insoluble salts.\n\u0084Reactions also involve the gain or loss of oxygen or hydrogen by substances.Oxidation is the gain of oxygen or loss of hydrogen. Reduction is the loss of oxygenor gain of hydrogen.\nEXERCISES\n1. Which of the statements about the reaction below are incorrect?\n2PbO(s) + C(s) \u2192 2Pb(s) + CO2(g)\n(a) Lead is getting reduced.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nEXERCISES\n1. Which of the statements about the reaction below are incorrect?\n2PbO(s) + C(s) \u2192 2Pb(s) + CO2(g)\n(a) Lead is getting reduced.\n(b) Carbon dioxide is getting oxidised.\n(c) Carbon is getting oxidised.\n(d) Lead oxide is getting reduced.\n(i) (a) and (b)\n(ii) (a) and (c)\n(iii) (a), (b) and (c)\n(iv) all\n2. Fe2O3 + 2Al \u2192 Al2O3 + 2Fe\nThe above reaction is an example of a\n(a) combination reaction.\n(b) double displacement reaction.Chemical Reactions and Equations 15(c) decomposition reaction.\n(d) displacement reaction.\n3. What happens when dilute hydrochloric acid is added to iron fillings? Tick the\ncorrect answer.\n(a) Hydrogen gas and iron chloride are produced.\n(b) Chlorine gas and iron hydroxide are produced.\n(c) No reaction takes place.\n(d) Iron salt and water are produced.",
  "What happens when dilute hydrochloric acid is added to iron fillings? Tick the\ncorrect answer.\n(a) Hydrogen gas and iron chloride are produced.\n(b) Chlorine gas and iron hydroxide are produced.\n(c) No reaction takes place.\n(d) Iron salt and water are produced.\n4. What is a balanced chemical equation? Why should chemical equations be\nbalanced?\n5. Translate the following statements into chemical equations and then balance them.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n4. What is a balanced chemical equation? Why should chemical equations be\nbalanced?\n5. Translate the following statements into chemical equations and then balance them.\n(a) Hydrogen gas combines with nitrogen to form ammonia.\n(b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.\n(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride\nand a precipitate of barium sulphate.\n(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen\ngas.\n6. Balance the following chemical equations.\n(a) HNO3 + Ca(OH)2 \u2192 Ca(NO3)2 + H2O\n(b) NaOH + H2SO4 \u2192 Na2SO4 + H2O\n(c) NaCl + AgNO3 \u2192 AgCl + NaNO3\n(d) BaCl2 + H2SO4 \u2192 BaSO4 + HCl\n7. Write the balanced chemical equations for the following reactions.",
  "Write the balanced chemical equations for the following reactions.\n(a) Calcium hydroxide + Carbon dioxide  \u2192  Calcium carbonate + Water\n(b) Zinc + Silver nitrate  \u2192  Zinc nitrate + Silver\n(c) Aluminium + Copper chloride  \u2192  Aluminium chloride + Copper",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n(a) Calcium hydroxide + Carbon dioxide  \u2192  Calcium carbonate + Water\n(b) Zinc + Silver nitrate  \u2192  Zinc nitrate + Silver\n(c) Aluminium + Copper chloride  \u2192  Aluminium chloride + Copper\n(d) Barium chloride + Potassium sulphate \u2192 Barium sulphate + Potassium chloride\n8. Write the balanced chemical equation for the following and identify the type of\nreaction in each case.\n(a) Potassium bromide(aq) + Barium iodide(aq) \u2192  Potassium iodide(aq) +\nBarium bromide(s)\n(b) Zinc carbonate(s) \u2192  Zinc oxide(s) + Carbon dioxide(g)\n(c) Hydrogen(g) + Chlorine(g)  \u2192  Hydrogen chloride(g)\n(d) Magnesium(s) + Hydrochloric acid(aq)  \u2192  Magnesium chloride(aq) + Hydrogen(g)\n9. What does one mean by exothermic and endothermic reactions? Give examples.\n10. Why is respiration considered an exothermic reaction? Explain.\n11.",
  "What does one mean by exothermic and endothermic reactions? Give examples.\n10. Why is respiration considered an exothermic reaction? Explain.\n11. Why are decomposition reactions called the opposite of combination reactions?\nWrite equations for these reactions.Science 16Group  Activity\nPerform the following activity.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\n11. Why are decomposition reactions called the opposite of combination reactions?\nWrite equations for these reactions.Science 16Group  Activity\nPerform the following activity.\n\u0084Take four beakers and label them as A, B, C and D.\n\u0084Put 25 mL of water in A, B and C beakers and copper sulphate solution in beaker D.\n\u0084Measure and record the temperature of each liquid contained in the beakers above.\n\u0084Add two spatulas of potassium sulphate, ammonium nitrate, anhydrous copper\nsulphate and fine iron fillings to beakers A, B, C and D respectively and stir.\n\u0084Finally measure and record the temperature of each of the mixture above.\nFind out which reactions are exothermic and which ones are endothermic in nature.12. Write one equation each for decomposition reactions where energy is supplied in\nthe form of heat, light or electricity.\n13. What is the difference between displacement and double displacement reactions?\nWrite equations for these reactions.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS -TEXTBOOK NOTES.txt\nthe form of heat, light or electricity.\n13. What is the difference between displacement and double displacement reactions?\nWrite equations for these reactions.\n14.  In the refining of silver, the recovery of silver from silver nitrate solution involved\ndisplacement by copper metal. Write down the reaction involved.\n15. What do you mean by a precipitation reaction? Explain by giving examples.16. Explain the following in terms of gain or loss of oxygen with two examples each.\n(a) Oxidation\n(b) Reduction\n17. A shiny brown coloured element \u2018X\u2019 on heating in air becomes black in colour.\nName the element \u2018X\u2019 and the black coloured compound formed.\n18. Why do we apply paint on iron articles?19. Oil and fat containing food items are flushed with nitrogen. Why?20. Explain the following terms with one example each.\n(a) Corrosion\n(b) Rancidity",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS.txt\nChemical Reactions & \nequations \nPower Point Presentation END",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\nVery Short Answer Type Questions [2 Marks]",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n1.  \u201cWe need to balance a skeletal chemical equation.\u201d Give reason to justify the \nstatement.  \n2. Giving an example list two information which make a chemical equation \nmore  useful (informative).  \n3. Name the reducing agent in the following reaction:  \n     3MnO 2 + 4Al \u2014\u2014\u2014\u2014  > 3Mn + 2Al 2O3 \nState which is more reactive, Mn or Al and why?  \n4. (i) Write a balanced chemical equation for process of photosynthesis.  \n   (ii)When do desert plants take up carbon dioxide and perform \nphotosynthe sis? \n5. What is observed when a solution of potassium iodide solution is added to \na solution of lead nitrate? Name the type of reaction. Write a balanced \nchemical  equation to represent the above chemical reaction.  \n6. Write balanced chemical equations for the fol lowing reactions.",
  "5. What is observed when a solution of potassium iodide solution is added to \na solution of lead nitrate? Name the type of reaction. Write a balanced \nchemical  equation to represent the above chemical reaction.  \n6. Write balanced chemical equations for the fol lowing reactions.  \n(i) Silver bromide on exposure to sunlight decomposes into silver and \nbromine,  \n(ii) Sodium metal reacts with water to form sodium hydroxide and hydrogen \ngas.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n(i) Silver bromide on exposure to sunlight decomposes into silver and \nbromine,  \n(ii) Sodium metal reacts with water to form sodium hydroxide and hydrogen \ngas. \n7. Identify the type of reaction(s) in the following equations.  \n(i)CH 4 + 2O 2 ----\uf0e0 CO 2 + 2 H2O \n(ii) Pb(NO 3)2 + 2KI \u2014\u2014\u2013>Pbl 2 + 2KNO 3 \n(iii) CaO +  H2O \u2014\u2014\u2013> Ca(OH) 2 \n(iv) CuSO 4 + Zn \u2014\u2014\u2013> ZnSO 4 + Cu  \n8. Write balanced equation for the reaction between magnesium and \nhydrochloric acid. Name the products obtained, identify the type of reaction.  \n9. Describe an activity to observe what happens when quick lime is added to \nwater taken in a beaker. State two important observations and name the type \nof reaction taking place.  \n10.",
  "Name the products obtained, identify the type of reaction.  \n9. Describe an activity to observe what happens when quick lime is added to \nwater taken in a beaker. State two important observations and name the type \nof reaction taking place.  \n10. What is the colour of ferrous sulphate crystals? How does this colour change \nafter heating?  \n11. Why does the colour of copper sulphate solution change when an iron nail is \ndipped in it? Write two observations.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\nafter heating?  \n11. Why does the colour of copper sulphate solution change when an iron nail is \ndipped in it? Write two observations.  \n12. Translate the following statement into chemical equation and then balance it : \nBarium chloride reacts with aluminium sulphate to gi ve aluminium chloride \nand a precipitate of barium sulphate. State the two types in which this reaction \ncan be classified.  \n13. Why decomposition reactions are called the opposite of combination \nreactions?  Write equations for these reactions.  \n14. AgN0 3 (aq) + NaCl( aq)\u2014\u2014\u2014\u2014\u2014\u2014 \u2013 > AgCl (s)\u2193 + NaN0 3(aq) \nFeS + H 2S0 4\u2014\u2014\u2014\u2014 - > FeS0 4 + H 2S\u2191 \nConsider the above mentioned two chemical equations with two different \nkinds of arrows (\u2191and \u2193) along with product. What do these two different \narrows indicate?  \n15.",
  "What do these two different \narrows indicate?  \n15. Hydrogen being a highly infla mmable gas and oxygen being a supporter of \ncombustion, yet water which is a compound made up of hydrogen and oxygen",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\narrows indicate?  \n15. Hydrogen being a highly infla mmable gas and oxygen being a supporter of \ncombustion, yet water which is a compound made up of hydrogen and oxygen \nis used to extinguish fire. Why?  16. Using a suitable chemical equation, justify that some chemical reactions are \ndetermined by:  \n(i) change in c olour, (ii) change in temperature.  \n17. (a) A solution of substance \u2018X\u2019 is used for white washing. What is the \nsubstance \u2018X\u2019? State the chemical reaction of \u2018X\u2019 with water.  \n(b) Why does the colour of copper sulphate solution change when an iron nail \nis dipped i n it? \n18. Write the balanced equation for the following reaction and identify the type of \nreaction in each case.  \n(i) Potassium bromide + Barium iodide \u2014-> Potassium iodide + Barium \nbromide.  \n(ii) Hydrogen(g) + Chlorine(g) \u2014-> Hydrogen chloride(g)  \n19.",
  "(i) Potassium bromide + Barium iodide \u2014-> Potassium iodide + Barium \nbromide.  \n(ii) Hydrogen(g) + Chlorine(g) \u2014-> Hydrogen chloride(g)  \n19. A zinc plate was  put into a solution of copper sulphate kept in a glass \ncontainer. It was found that blue colour of the solution gets fader and fader",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n19. A zinc plate was  put into a solution of copper sulphate kept in a glass \ncontainer. It was found that blue colour of the solution gets fader and fader \nwith the passage of time. After few days, when zinc plate was taken out of the \nsolution, a number of holes were observed o n it. \n(i) State the reason for changes observed on the zinc plate.  \n(ii) Write the chemical equation for the reaction involved.  \n20. A white salt on heating decomposes to give brown fumes and a residue is \nleft behind.  \n(i) Name the salt.  \n(ii) Write the equation f or the decom -position reaction.  \n21. When a solution of potassium iodide is added to a solution of lead nitrate in a \ntest tube, a reaction takes place.  \n(a) What type of reaction is this?  \n(b) Write a balanced chemical equation to represent the above reaction.  \n22. Define combination reaction. Give one example of a combination reaction  \nwhich is also exothermic  \n23. (a) Classify the following reactions into different types.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n22. Define combination reaction. Give one example of a combination reaction  \nwhich is also exothermic  \n23. (a) Classify the following reactions into different types.  \n       (i) Na 2SO 4 + BaCl 2 -----\uf0e0 BaSO 4 + NaCl  \n       (ii) CaO  + H 2O  --------\uf0e0 Ca(OH) 2 \n        (iii) CaCO 3 ----------\uf0e0 CaO + CO 2 \n(b) Which of the above reaction(s) is/are precipitation reaction(s)? Why a \nreaction        is called precipitation reaction?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n24. Write a balanced chemical equation for the reaction between sodium chloride  \nand silver nitrate  indicating the physical state of the reactants and the \nproducts.  \n25. What is a redox reaction? When a magnesium ribbon burns in air with a \ndazzling flame and forms a white ash, is magnesium oxidized or reduced? \nWhy?  \n26. Write any two observations in an activity w hich may suggest that a \nchemical  reaction has taken place. Give an example in support of your \nanswer.  \n27. When the powder of a common metal is heated in an open china dish, its \ncolour turns black. However, when hydrogen is passed over the hot black \nsubstance s o formed, it regains its original colour. Based on the above \ninformation, answer the following questions.  \n(i) What type of chemical reaction takes place in each of the two given steps?  (ii) Name the metal initially taken in the powder form. Write balanced chemical \nequations for both reactions.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n(i) What type of chemical reaction takes place in each of the two given steps?  (ii) Name the metal initially taken in the powder form. Write balanced chemical \nequations for both reactions.  \n28. In electrolysis of water, why is the volume of gas collected over one electrode \ndouble that of gas collected over the other electrode?  \n29. Name the products formed on strongly heating ferrous sulphate crystals. What \ntype of chemical reaction occurs in this change?  \n30. What is an oxidation reaction? Give an example of oxidation reaction. Is \noxidation an exothermic or an endothermic reaction?  \n31. Describe an activity to demonstrate the change that takes place when white \nsilver chlor ide is kept in sunlight. State the type of chemical reaction which \ntakes place.  \n32. When magnesium ribbon burns in air or oxygen, a product is formed. State \nthe type of chemical reaction and name the product formed in the reaction. \nWrite balanced chemical equa tion of this reaction.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\nthe type of chemical reaction and name the product formed in the reaction. \nWrite balanced chemical equa tion of this reaction.  \n33. Distinguish between a displacement reaction and a double displacement \nreaction. Identify the displacement and the double displacement reaction from \nthe following reactions.  \n(i) CuSO 4 + Zn  ----\uf0e0  ZnSO 4 +Cu \n(ii) Pb(NO 3)2 + KI -----\uf0e0 PbI 2 + 2 KNO 3",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\nShort Answer Type Questions (II) [3 Marks]  \n \n34. Write the chemical equation of the reaction in which the following changes \nhave taken place with an example of each:   \n(i) Change in colour  \n(ii) Change in temperature  \n(iii) Formation of precipitate  \n35. State the type of chemical reactions and chemical equations that take place in \nthe following:  \n(i) Magnesium wire is burnt in air.  \n(ii) Electric current is passed through water.  \n(iii) Ammonia and hydrogen chloride gases \u2018are mixed.  \n36. (a) Write the essential c ondition for the following reaction to take place:  \n                  2AgBr \u2014-> 2Ag + Br 2 \nWrite one application of this reaction.  \n(b) Complete the following chemical equation of a chemical reaction  \n                Heat  \n     2FeS0 4 \u2014\uf0e0 Fe2O3  +\u2026\u2026. + \u2026\u2026  \n(c) What happens when water is added to quick lime? Write chemical              \nequation.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n37. 2g of ferrous sulphate crystals are heated in a dry boiling tube.  \n(i) List any two observations.  \n(ii) Name the type of chemical reaction taking place.  \n(iii) \u2018Write the chemical equation for the reaction.  \n38. Write chemical equation reactions taking place when carried out with the help \nof \n(a) Iron reacts with steam  (b) Magnesium reacts with dil HCl  \n(c) Copper is heated in air.  \n39. Which products will be obtained when lead nit rate is heated simply? Write \nbalanced chemical equation for the reaction? State the type of chemical \nreaction that occur in the change.  \n40. What is meant by skeletal type chemical equation? What does it represent? \nUsing the equation for electrolytic decomposit ion of water, differentiate \nbetween a skeletal chemical equation and a balanced chemical equation.  \n41. What is rancidity? Mention any two ways by which rancidity can be prevented.  \n42. Write balanced chemical equation for the reactions that take place during",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n41. What is rancidity? Mention any two ways by which rancidity can be prevented.  \n42. Write balanced chemical equation for the reactions that take place during \nrespir ation. Identify the type of combination reaction that takes place during \nthis process and justify the name. Give one more example of this type of \nreaction.  \n43. What is redox reaction? Identify the substance oxidised  and the substance \nreduced in the following reactions.  \n(i)2PbO + C \u2014\u2013> 2Pb + CO 2 \n(ii)MnO 2 + 4HCl \u2014\u2013> MnCl 2 + 2H 20 + Cl 2 \n44. Write the balanced chemical equations for the following reaction and identify \nthe type of reaction.  \nThermite reaction, iron (III) oxide reacts with aluminium and gives molten iron \nand aluminium oxide.  \n45. A solution of potassium chloride when mixed with silver nitrate solution, an \ninsoluble white substance is formed.",
  "Thermite reaction, iron (III) oxide reacts with aluminium and gives molten iron \nand aluminium oxide.  \n45. A solution of potassium chloride when mixed with silver nitrate solution, an \ninsoluble white substance is formed. Write the chemical reaction involved and \nalso mention the type of the chemica l reaction?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\ninsoluble white substance is formed. Write the chemical reaction involved and \nalso mention the type of the chemica l reaction?  \n46. Write balanced equations for the following mentioning the type of reaction \ninvolved.  \n(i) Aluminium + Bromine \u2014\u2013> Aluminium bromide  \n(ii) Calcium carbonate \u2014\u2013> Calcium oxide + Carbon dioxide  \n(iii) Silver chloride \u2014\u2013>Silver + Chlorine  \n47. (a) Why is res piration considered as an exothermic reaction?  \n(b) Define the terms oxidation and reduction.  \n(c) Identify the substance that is oxidised and reduced in the following \nreaction  \n               Zn + CuO  ----\uf0e0 ZnO + Cu",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n48. What is meant by  \n(i) precipitation reac tion, \n(ii) exothermic reaction,  \n(iii) oxidation reaction?  \nWrite balanced chemical equations for an example of each . \n49. You might have noted that when copper powder is heated in a china dish, the \nsurface of copper powder becomes coated with a black colour  substance.  \n(i) How has this black coloured substance formed?  \n(ii) What is that black substance?  \n(iii) Write the chemical equation of the reaction that takes place.  \n50. (a) What happens chemically when quicklime is added to water filled in a     \nbucket?  \n(b) On  what basis is a chemical equation balanced?  \n(c ) What change in colour is observed when white silver chloride is left    \nexposed to sunlight? State the type of chemical reaction in this change.  51. What happens when an aqueous solution of sodium sulphate reac ts with an \naqueous solution of barium chloride? State the physical conditions of",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\naqueous solution of barium chloride? State the physical conditions of \nreactants in which the reaction between them will not take place. Write the \nbalanced chemical equation for the reaction and name the type of reaction.  \n52. When you have mixed the solutions of lead(II) nitrate and potassium iodide,  \n(i) what was the colour of the precipitate formed and can you name the \nprecipitate?  \n(ii) Write the balanced chemical equation for this reaction.  \n(iii) Is this also a double displac ement reaction?  \n53. Name the type of reaction represented by the following equation:  \n(i)                 CaO + H 2O  ---\uf0e0 Ca(OH) 2 \n(ii) 3BaCl 2  + Al 2(SO 4)3  ---\uf0e0 3 BaSO 4 + 2 AlCl 3 \n                    heat \n(iii) 2 FeSO 4 ----------------- \uf0e0  Fe2O3 + SO 2 + SO 3 \n54.",
  "Write the chemical equation of the reaction in which the following changes \nhave taken place with an example of each:   \n(i) Change in colour  \n(ii) Change in temperature  \n(iii) Formation of precipitate",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\nhave taken place with an example of each:   \n(i) Change in colour  \n(ii) Change in temperature  \n(iii) Formation of precipitate  \n55. Balance the following chemical equations.  \n(i) BaCl 2   + H 2SO 4 ------\uf0e0 BaSO 4  + HCl  \n(ii) Ca(OH) 2   + HNO 3  ----\uf0e0 Ca(NO 3)2 + H 2O \n(iii)Pb(NO 3)2 ------\uf0e0 PbO +NO 2 +O 2 \n(iv) MnO 2 + HCl  ----\uf0e0 MnCl 2 + H 2O + Cl 2 \n56. Balance the following chemical reactions and identify the type of reaction.",
  "Balance the following chemical reactions and identify the type of reaction.  \n(a) Mg (s) + Cl 2 (g)  ---\uf0e0 MgCl 2(s) \n(b) HgO (s)  --\uf0e0 Hg(l) + O 2(g) \n(c) Na(s)  + S (s) ----------\uf0e0 Na2S(s) \n(d) TiCl4 (l) + Mg (s)  ----\uf0e0 Ti(s) + MgCl 2(s) \n(e) CaO (s) + SiO 2(s)  ---\uf0e0 CaSiO 3(s) \n(f) H2O2(l)  --------\uf0e0 H2O(l) + O 2(g) \n57. During the reaction of some metas with dilute hydrochloric acid, following \noberservations were made.  \n(a) Silver meta does not show any change  \n(b) The temperature of the reaction mixture rises when aluminium (Al) is \nadded.  \n(c) The reaction os sodium metal is found to be highly explosive",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-SHORT ANSWER TYPE QUESTIONS.txt\n(a) Silver meta does not show any change  \n(b) The temperature of the reaction mixture rises when aluminium (Al) is \nadded.  \n(c) The reaction os sodium metal is found to be highly explosive  \n(d) Some bubbles of a gas are seen when lead (Pb) is reacted with acid.  \nExplain these observations givi ng suitable reasons.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nTest  items  \n \n \n \nLOB: Compare  the characteristics  of initial & final substances  in order to check  whether  the  \nchange is physical or chemical  \n \n1) A student  poured 100 mL  of water  in a bottle  and added 40 mL  vinegar  to it.  A balloon was  filled  \nwith 20 g baking  soda  and was  fixed at  the mouth of  the bottle.  Slowly  the shape  of the balloon  \nchanged, as  shown.  \n \n \n \nThe student  claims that  a chemical change  happened when  the two substances  were mixed.  Is \nthe claim made by  the student correct?  \n \n(a) Yes, as  a new substance  was formed  in the form of a gas. \n(b) Yes, as  the mass  remains  the same  throughout  the experiment.  \n(c) No, as  the formation of  bubbles in the mixture  shows  a physical  change.  \n(d) No, as  the change  in the shape  and size  of the balloon shows a physical  change.",
  "(c) No, as  the formation of  bubbles in the mixture  shows  a physical  change.  \n(d) No, as  the change  in the shape  and size  of the balloon shows a physical  change.  \nCorrect Answer: Option  (a) \n \n2) A student  makes a list of some  activities he  observes one  day.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\n2) A student  makes a list of some  activities he  observes one  day.  \n \n \n \n \nWhich  activity can  the student  classify  as a chemical  change?  \n \n(a) Activity 1,  as the  properties  of the  substances in  the mixture change.  \n(b) Activity 2,  as the  physical  state of  the apple  pie changes when  cut. \n(c) Activity 3,  as the shape  of the  can changes.  \n(d) Activity 4,  as the  shape  and size  of the  wooden  log changes.  \nCorrect Answer: Option  (a) \nLOB : Relate the substances  taking  part in the chemical  reaction  & substances  formed in the   \nchemical reaction in  order  to classify them as reactants & products  \n1) Sodium  and chlorine are  reacted and  as a result,  sodium chloride is  formed  which is  also  called  \ntable salt.  What option  gives  the reactants  and products  of the reaction?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\n(a) reactants -sodium; products - chlorine  \n(b) reactants -sodium  and table salt;  products - chlorine  \n(c) reactants -tables salt;  products - sodium and  chlorine  \n(d) reactants -sodium  and chlorine; products - sodium chloride  \nCorrect Answer: Option  (d) \n \n \n2) The image  shows some  chemical  reactions.  \n \n \n \nWhich  option identifies the reactants  and products  of the reactions?  \n \n(a)   \n(b)   \n(c)   \n(d)   \nCorrect Answer: Option  (c) \nLOB : Use chemical symbols  & chemical formulae correctly in order  to acquire the skill  of writing   \nchemical equations  \n1) A student  performs an  experiment  to form aluminium  chloride  from aluminium  and chlorine.  \nWhich  options  gives the chemical  equation  of the reaction?",
  "Which  options  gives the chemical  equation  of the reaction?  \n(a) Al + Cl2 \uf0e0\uf020AlCl 2 \n(b) 2Al + Cl2 \uf0e0\uf0202AlCl  \n(c) 2Al + 3Cl 2 \uf0e0\uf0202AlCl 3 \n(d) 3Al + 3Cl 2 \uf0e0\uf0203AlCl 3 \n \nCorrect Answer: Option  (c)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nCorrect Answer: Option  (c) \n \n \n2) A researcher  adds barium hydroxide  to hydrochloric  acid to  form a white -colored barium  \nchloride. Which option gives  the balanced chemical  equation of  the reaction?  \n \n(a) HCl + Ba(OH) 2 \uf0e0\uf020BaCl 2 + 2HOH  \n \n(b) 2HCl  + Ba(OH) 2 \uf0e0\uf020BaCl 2 + 2HOH  \n \n(c) 2HCl  + Ba(OH) 2 \uf0e0\uf020BaH 2 + 2HCl  + O2 \n \n(d) HCl + 2Ba(OH)  \uf0e0\uf0202BaCl 2 + 2HOH  + O2 \n \nCorrect Answer: Option  (b) \n \n \n \n \n \n \n \nLOB : Apply Law  of Conservation  of Mass  in order  to balance chemical  equations  \n1) A student  writes  a balanced  chemical  equation.",
  "Pb(s)  + CuCl 2(aq)  \uf0ae\uf020PbCl 2(aq)  + Cu(s)  \nWhich  option gives the number  of elements  on the LHS and RHS of the chemical  equation?  \n(a) \n \n \n(b) \n \n \n \n(c) \n \n \n(d) \n \n \n \nCorrect Answer: Option  (d) \n \n \n2) The image  shows a balanced  chemical equation  of the reaction  between sodium and chlorine  to \nform  sodium chloride.  \n \n \n \nWhich  option shows the number  of atoms on  both sides  of the reaction?  \n(a)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nWhich  option shows the number  of atoms on  both sides  of the reaction?  \n(a) \n \n \n(b) \n \n \n(c) \n \n \n(d) \n \n \nCorrect Answer: Option  (b)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nLOB: Categorize  the given reactions  as (combination/ decomposition) based  on the reactants &  \nproducts  of a chemical  reaction  \n1) A student  writes a chemical  equation  of the reaction between  carbon  monoxide  and hydrogen.  \nCO 2 + 2H 2   -> CH 3OH \nHow  can the  reaction be classified?  \n(a) The reaction  is an  example  of a combination reaction  as a compound  separates into  two \ncompounds.  \n(b) The reaction  is an  example  of a decomposition reaction  as a compound  dissociates into  \ntwo compounds.  \n(c) The reaction  is an  example of a combination reaction  as two compounds  react to form a \nsingle compound.  \n(d) The reaction  is an  example  of a decomposition reaction  as two compounds  react to  form \na single compound.",
  "(c) The reaction  is an  example of a combination reaction  as two compounds  react to form a \nsingle compound.  \n(d) The reaction  is an  example  of a decomposition reaction  as two compounds  react to  form \na single compound.  \nCorrect Answer: Option  (c) \n2) A student  learns  that  some  products are  formed as  a result of  combining  two compounds  while  \nsome compounds  are formed  as a result  of dissociation of  two compounds.  The image  shows",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nsome compounds  are formed  as a result  of dissociation of  two compounds.  The image  shows  \ntwo reactions.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nWhich  reaction is an example of a combination  reaction and  a decomposition reaction?  \n(a) both  the reactions are  examples  of combination  reaction  \n(b) both  the reactions are  examples  of a decomposition reaction  \n(c) reaction  P is an  example  of a combination  reaction while  reaction  Q is an  example  of a \ndecomposition  reaction  \n(d) P is an example  of a decomposition reaction  while  reaction Q is an example  of a \ncombination reaction  \nCorrect Answer: Option  (c)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nLOB: Classify the  given reaction  as displacement  or double  displacement  based  on the type  of  \nreactants  used  & products formed  \n1) A student  adds lead  and silver to  two different  test tubes containing an equal  amount  of copper  \nsulphate solution.  The student  observes  that the  color of  the solution in the test  tube  with  lead \nchanges. What  explains the  change  in the  colour of  the solution?  \n(a) A displacement  reaction  takes  place  as lead  replaces copper from the solution.  \n(b) A combination reaction  takes  place  as lead  combines with  sulpha te in the  solution.  \n(c) decomposition  reaction takes place  as copper  dissociates  from  sulphate  in the solution.  \n(d) A double  displacement reaction takes  place as  copper  dissociates  from sulphate and  \nlead  combines  with  sulphate in  the solution.",
  "(c) decomposition  reaction takes place  as copper  dissociates  from  sulphate  in the solution.  \n(d) A double  displacement reaction takes  place as  copper  dissociates  from sulphate and  \nlead  combines  with  sulphate in  the solution.  \nCorrect Answer: Option  (a) \n2) The chemical  reaction between  potassium chloride  and silver nitrate  is given by  the chemical",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nlead  combines  with  sulphate in  the solution.  \nCorrect Answer: Option  (a) \n2) The chemical  reaction between  potassium chloride  and silver nitrate  is given by  the chemical  \nequation.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nWhat can be  inferred  from the  chemical  equation?  \n(a) silver nitrate  and potassium undergo  a decomposition reaction  to form silver chloride  \nand potassium  nitrate  \n(b) silver nitrate  and potassium undergo  a displacement  reaction  to form silver chloride  \nand potassium nitrate  \n(c) silver nitrate  and potassium undergo  a combination reaction  to form silver chloride and  \npotassium  nitrate  \n(d) silver nitrate  and potassium undergo  double displacement  reaction  to form silver  \nchloride and potassium  nitrate  \nCorrect Answer: Option  (d) \n \n \nLOB: Predict the reaction  as Oxidation or  Reduction based  on the addition/ removal of  oxygen/   \nhydrogen/  electrons to  the reactants to  form products.  \n1) The image  shows a reaction between  zinc  and hydrogen.  \n Which  option shows oxidation?  \n(a) Zn \uf0ae\uf020Zn!\" \n(b) 2H! \uf0ae\uf020H2 \n(c) Zn!\"",
  "1) The image  shows a reaction between  zinc  and hydrogen.  \n Which  option shows oxidation?  \n(a) Zn \uf0ae\uf020Zn!\" \n(b) 2H! \uf0ae\uf020H2 \n(c) Zn!\" \uf0ae\uf020Zn \n(d) H 2  \uf0ae2H! \nCorrect Answer: Option  (a) \n \n \n2) The image  shows a reaction  between iron  oxide  and hydrogen.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\n2) The image  shows a reaction  between iron  oxide  and hydrogen.  \n \n \nWhich  option shows the compounds  undergoing oxidation  and reduction?  \n(a) \n \n \n \n(b) \n \n \n(c) \n \n \n(d) \n \n \nCorrect Answer: Option  (a) \n \n \n \n \n \nLOB: Observe  colour  change  in iron, copper  and silver  articles  over  time in  order  to outline the   \neffects  of corrosion  in our surroundings (real  life situations,  stating  any two)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nLOB: Observe  colour  change  in iron, copper  and silver  articles  over  time in  order  to outline the   \neffects  of corrosion  in our surroundings (real  life situations,  stating  any two)  \n \n1) A student  notices that  a new hammer  made of  iron is shiny  while an  old one kept  in the toolbox  \nfor long  has a reddish -brown  powder deposit  over it.  What  does the  change in  colour  of the  \nhammer indicate?  \n(a) effect of  moisture on metals  \n(b) iron hammer  turns brown  after  some time  \n(c) effects of  kept in a box for a longer duration  \n(d) iron changes  colour when kept  with other tools  \nCorrect Answer: Option  (a) \n2) A student  notices that  her silver jewellery  turned dull  and had a gray -black film over  it after  \nwearing for  a few months.  What results  in the change  in colour  of the silver  metal?",
  "What results  in the change  in colour  of the silver  metal?  \n(a) dust deposits  over  the jewellery  which changes  its colour",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\n(b) the jewellery  comes in  contact  with  air, moisture, and acids  and corrodes  \n(c) the polish  over the jewellery  was removed  after wearing  for a few months  \n(d) silver breaks  due to wear and tear and turns  its colour changes due  to rusting  \nCorrect Answer: Option  (b) \n \n \nLOB: Detect changes  in smell,  colour, taste of  food items  overtime, in order to explain effects  of  \noxidation on  food items  \n \n1) A student  learns  that  food  companies fill  bags of  chips  with nitrogen gas. What  is the purpose  \npacking  it with nitrogen?  \n(a) it prevents  rancidity  of chips  \n(b) it keeps  the mosquitoes  away  from chips  \n(c) it keeps  the chips  dry if the  pack falls  in water  \n(d) prevents chips  from  spilling out when  the pack is  opened  \n \nCorrect Answer: Option  (a)",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nCorrect Answer: Option  (a) \n \n \n \n \n2) A student  notices that  the bread kept  out has  a green  coloured coating over it  after a few days.  \nWhat explains  the reason for  the student\u2019s  observation?  \n(a) the oils in  the bread  oxidises and  causes rancidity  \n(b) bread comes  in contact  with atmospheric moisture  and corrodes  \n(c) the oils in  the bread  reduces and  cause the  change  in the colour of  the bread  \n(d) comes in  contact with the  atmospheric nitrogen  and a layer  deposit over  it",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nCorrect Answer: Option  (a) \nSuggested  Teacher  Resources  \n1 Activity      \nObjective  Categorize the  given reactions  as (combination/ decomposition)  based  on the  \nreactants & products of  a chemical reaction.  \nPrerequisite  Identify the changes that  a reaction  mixture undergoes during a chemical  \nreaction, what are reactants,  what are products  \nMaterial  \nRequired  Test tubes,  boiling tube,  distilled  water,  burner,  sugar, iron  fillings,  sulphur  \npowder  \nVocabulary  Combination Reaction:  A reaction  in which  a single product  is formed from  \ntwo or  more reactants  is known as  a combination  reaction.  \n \nDecomposition  Reaction:  A reaction in which a single substance  decomposes  \nto give  two or  more  substances.  \n  \nProcedure  Procedure  1: \n1. Take a small amount  of iron fillings  and sulphur  powder  in a boiling  \ntube.  \n2.",
  "Procedure  Procedure  1: \n1. Take a small amount  of iron fillings  and sulphur  powder  in a boiling  \ntube.  \n2. Heat the boiling  tube strongly over the flame  of a burner or  spirit lamp  \nand observe changes.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nProcedure  2: \n1. Take about  2 g sugar  crystals in  a dry boiling  tube.  (Note the  colour  of \nthe crystals.)  \n2. Heat the boiling  tube over  the flame of a burner  or spirit  lamp  and \nobserve  changes.  \nReflection  \nQuestions   \nText to  real \nworld  \nconnection  Propane is  a fuel used  to provide  heat for  some  homes. It  is stored  in large  \ntanks as  shown here.  Can you predict  the chemical  equation  for burning of  \npropane?  \n \n \nBeyond the  \nclassroom  What type of reaction takes  place inside the  human  and plant cells?  \n \n \n \n \nMaterial  \nrequired  Fresh  potato  chips, 2 glass  jars with  lid, Aluminium foil.  \nProcedure  1. Wrap  the glass jar  with aluminium  foil. Tape  the foil  in place so  that  no \nlight can enter  the container.  \n2.",
  "Procedure  1. Wrap  the glass jar  with aluminium  foil. Tape  the foil  in place so  that  no \nlight can enter  the container.  \n2. Place fresh potato chips  in the foil -wrapped  jar and  in a similar  clear jar  \nwithout foil around it.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nActivity  \n    Reaction  No. Materials  \nused  Chemicals  \nused  Describe  the \nreactants  \n(number  of \nreactants)  Procedure  Describe  \nthe \nproducts  \n(number  of \nproducts)  Type  of \nreaction  \nCalcium  \nOxide  + \nwater        \nHeating  \nSugar        \n  \n 3. Taste the potato chips  and rate their  flavour on  a 5-point  scale,  1 being  \nextremely  dislike the  flavour and  5 being extremely  like the flavour.  \n(Enter your  data in  a table.)  \n4. Place the  two jars on a window  sill where  they will be  exposed to  \nsunlight.  \n5. Taste potato  chips from each  jar at  intervals of  1-2 days for  1-2 weeks  \nand record  the taste of  potatoes in  both  the jars.  \n6. Make a graph  of your data, noting the  flavor  of the potato  chips stored  \nthese two  ways versus  storage  time.",
  "6. Make a graph  of your data, noting the  flavor  of the potato  chips stored  \nthese two  ways versus  storage  time. The  y-axis should  be the  flavor  \nscore  and the x-axis  the time  in days.  \nReflection  \nquestions  1. What effect  does the aluminium foil have on  the taste of potatoes after 2 \nweeks?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-TEST QUESTIONS.txt\nscore  and the x-axis  the time  in days.  \nReflection  \nquestions  1. What effect  does the aluminium foil have on  the taste of potatoes after 2 \nweeks?  \n2. Is there anything  else that  will affect  the taste of  potatoes over  2 weeks  \napart from the  sunlight?",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nChemical Reactions and Equations\nIntroduction to Chemical Reactions and Equations\nPhysical and chemical changes\nChemical change - one or more new substances with new physical and chemical properties\nare formed.\nExample: Fe(s)\u00a0 + \u00a0CuSO 4(aq) \u2192FeSO 4(aq) +Cu(s)\u00a0\n \u00a0 \u00a0 \u00a0 (Blue)\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 (Green)\u00a0 \u00a0 \u00a0 \u00a0\nHere, when copper sulphate reacts with iron, two new substances, i.e., ferrous sulphate and\ncopper are formed.\nPhysical change - change in colour or state occurs but no new substance is formed.\nExample: Water changes to steam on boiling but no new substance is formed(Even though\nsteam and water look different when they are made to react with a piece of Na, they react\nthe same way and give the exact same products). This involves only change in state (liquid\nto vapour).\u00a0\nObservations that help determine a chemical reaction\nA chemical reaction can be determined with the help of any of the following observations:\na) Evolution of a gas\nb) Change in temperature",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nObservations that help determine a chemical reaction\nA chemical reaction can be determined with the help of any of the following observations:\na) Evolution of a gas\nb) Change in temperature\nc) Formation of a precipitate\nd) Change in colour\ne) Change of state\nChemical reaction\nChemical reactions are chemical changes in which reactants transform into products by\nmaking or breaking of bonds(or both) between different atoms.\nTypes of chemical reactionsTaking into consideration different factors, chemical reactions are grouped into multiple\ncategories.\nFew examples are:\n\u25cfCombination\n\u25cfDecomposition\n\u25cfSingle Displacement\n\u25cfDouble displacement\n\u25cfRedox\n\u25cfEndothermic\n\u25cfExothermic\n\u25cfPrecipitation\n\u25cfNeutralisation\nChemical Reactions and Equations I\nWord equation\nA\u00a0 word equation is a\u00a0chemical reaction\u00a0expressed in words rather than\u00a0chemical\nformulas.\u00a0It helps identify the reactants and products in a chemical reaction.\nFor example,\u00a0\nSodium + Chlorine \u2192 Sodium chloride",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nformulas.\u00a0It helps identify the reactants and products in a chemical reaction.\nFor example,\u00a0\nSodium + Chlorine \u2192 Sodium chloride\nThe above equation means: \"Sodium reacts with chlorine to form sodium chloride.\"\u00a0\nSymbols of elements and their valencies\nA symbol is the chemical code for an element. Each element has one or two letter atomic\nsymbol, which is the abbreviated form of its name.\nValency is the combining capacity of an\u00a0element. It can be considered as the number of\nelectrons lost, gain or shared by an atom when it combines with another atom to form a\nmolecule.\nWriting chemical equations\nRepresentation of a chemical reaction in terms of symbols and chemical formulae of the\nreactants and products is known as a chemical equation.\nZn(s) +dil.H2SO 4(aq) \u2192ZnSO 4(aq) +H2(\u2191)\n\u00a0(Reactants)\u00a0 \u00a0(Products)\n\u2022 For solids, the symbol is \"(s)\".\n\u2022 For liquids, it is \"(l)\".",
  "Zn(s) +dil.H2SO 4(aq) \u2192ZnSO 4(aq) +H2(\u2191)\n\u00a0(Reactants)\u00a0 \u00a0(Products)\n\u2022 For solids, the symbol is \"(s)\".\n\u2022 For liquids, it is \"(l)\".\n\u2022 For gases, it is \"(g)\".\u2022 For aqueous solutions, it is \"(aq)\".",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nZn(s) +dil.H2SO 4(aq) \u2192ZnSO 4(aq) +H2(\u2191)\n\u00a0(Reactants)\u00a0 \u00a0(Products)\n\u2022 For solids, the symbol is \"(s)\".\n\u2022 For liquids, it is \"(l)\".\n\u2022 For gases, it is \"(g)\".\u2022 For aqueous solutions, it is \"(aq)\".\n\u2022 For gas produced in the reaction, it is represented by \"(\u2191)\".\n\u2022 For precipitate formed in the reaction, it is represented by \"(\u2193)\".\nBalancing of a Chemical Reaction\nConservation of mass\nAccording to the law of conservation of mass, no atoms can be created or destroyed in a\nchemical reaction, so the number of atoms for each element in the reactants side has to\nbalance the number of atoms that are present in the products side.\nIn other words, the total mass of the products formed in a chemical reaction is equal to the\ntotal mass of the reactants participated in a chemical reaction.",
  "In other words, the total mass of the products formed in a chemical reaction is equal to the\ntotal mass of the reactants participated in a chemical reaction.\nBalanced chemical equation\nThe chemical equation in which the number of atoms of each element\u00a0in the reactants side\nis equal to that of the products side is called a balanced chemical equation.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nBalanced chemical equation\nThe chemical equation in which the number of atoms of each element\u00a0in the reactants side\nis equal to that of the products side is called a balanced chemical equation.\nSteps for balancing chemical equations\nHit and trial method: While balancing the equation, change the coef\ufb01cients (the numbers in\nfront of the compound or molecule) so that the number of atoms of each element is same\non each side of the chemical equation.\u00a0\nShort-cut technique for balancing a chemical equation\nExample:\naCaCO 3+bH3PO 4\u2192cCa 3(PO 4)2+dH2CO 3\nSet up a series of simultaneous equations, one for each element.",
  "Short-cut technique for balancing a chemical equation\nExample:\naCaCO 3+bH3PO 4\u2192cCa 3(PO 4)2+dH2CO 3\nSet up a series of simultaneous equations, one for each element.\nCa: a=3c\nC:\u00a0 \u00a0a=d\nO:\u00a0 \u00a03a+4b=8c+3d\nH:\u00a0 \u00a03b=2d\nP:\u00a0 \u00a0 b=2c\nLet's set c=1\nThen a=3 and\nd=a=3\nb=2c=2So a=3; b=2; c=1; d=3\nThe balanced equation is\n3CaCO 3+ 2H 3PO 4\u2192Ca3(PO 4)2+ 3H 2CO 3\nChemical Reactions and Equations II\nTypes of chemical reactions\nTaking into consideration different factors, chemical reactions are grouped into multiple\ncategories.\nFew examples are:\n\u25cfCombination",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nChemical Reactions and Equations II\nTypes of chemical reactions\nTaking into consideration different factors, chemical reactions are grouped into multiple\ncategories.\nFew examples are:\n\u25cfCombination\n\u25cfDecomposition\n\u25cfSingle Displacement\n\u25cfDouble displacement\n\u25cfRedox\n\u25cfEndothermic\n\u25cfExothermic\n\u25cfPrecipitation\n\u25cfNeutralisation\nCombination reaction\nIn a combination reaction, two elements or one element and one compound or two\ncompounds combine\u00a0to give one single product.\nH2+Cl2\u2192 2HCl\nelement + element \u2192 compound\n2CO +O2\u2192 2CO 2\ncompound + element \u2192 compound\nNH 3+HCl \u2192NH 4Cl\ncompound + compound \u2192 compound\nDecomposition reaction\nA single reactant decomposes on the application of heat or light or electricity to give two or\nmore products.\nTypes of decomposition reactions:\na. Decomposition reactions which require heat - thermolytic decomposition or thermolysis.\nThermal decomposition of HgO\nb. Decomposition reactions which require light - photolytic decomposition\u00a0or\u00a0photolysis.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nThermal decomposition of HgO\nb. Decomposition reactions which require light - photolytic decomposition\u00a0or\u00a0photolysis.\nPhotolytic decomposition of H2O2\nc. Decomposition reactions which require electricity - electrolytic decomposition or\nelectrolysis.\nElectrolytic decomposition of H 2O\nDisplacement reaction\nMore reactive element displaces a less reactive element from its compound or solution.i)Zn(s) +CuSO 4(aq) \u2192ZnSO 4(aq) +Cu(s)\nii)Cu(s) + 2AgNO 3(aq) \u2192Cu(NO 3)2(aq) + 2Ag (s)\nDouble displacement reaction\nAn exchange of ions between the reactants takes place to give new products.\nFor example,\u00a0Al 2(SO4)3(aq) + 3Ca( OH)2(aq) \u2192 2Al (OH)3(aq) + 3CaSO 4(s)\nPrecipitation reaction\nAn insoluble compound called precipitate forms when two solutions containing soluble salts\nare combined.",
  "For example, Pb( NO 3)2(aq) + 2KI (aq) \u2192 2KNO 3(aq) +PbI 2(\u2193)(s)(yellow )\nRedox reaction\nOxidation and reduction take place simultaneously.\nOxidation:  Substance loses electrons or gains oxygen or loses hydrogen.",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nRedox reaction\nOxidation and reduction take place simultaneously.\nOxidation:  Substance loses electrons or gains oxygen or loses hydrogen.\nReduction:  Substance gains electrons or loses oxygen or gains hydrogen.\nOxidising agent  - a substance that oxidises another substance and self-gets reduced.\nReducing agent - a substance that reduces another substance and self-gets oxidised.\nExamples:\n1.Fe(s) +CuSO 4(aq) \u2192FeSO 4(aq) +Cu(s)\u00a0 \u00a0 \u00a0 \u00a0(Blue)\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 (Green)\nFe\u2192Fe+2+ 2e \u2212 \u00a0(oxidation ) ; Fe - reducing agent.\nCu+2+ 2e \u2212 \u2192Cu(s)\u00a0(reduction ) ; Cu - oxidising agent.\n2.ZnO +C\u2192Zn+CO\nZnO reduces to Zn\u00a0\u2192 reduction\nC oxidises to CO \u2192 oxidation\nZnO - Oxidising agent\nC - Reducing agent\nEndothermic and exothermic reaction\nExothermic reaction - heat is evolved during a reaction.",
  "Most of the combination reactions\nare exothermic.\nAl+Fe2O3\u2192Al2O3+Fe+heat\nCH 4+ 2O 2\u2192CO 2+ 2H 2O+heat\nEndothermic - Heat is required to carry out the reaction.\n6CO 2+ 6H 2O+Sunlight \u2192C6H12O6+ 6O 2\n\u00a0 \u00a0 \u00a0 \u00a0Glucose",
  "CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS-REVISION NOTES.txt\nare exothermic.\nAl+Fe2O3\u2192Al2O3+Fe+heat\nCH 4+ 2O 2\u2192CO 2+ 2H 2O+heat\nEndothermic - Heat is required to carry out the reaction.\n6CO 2+ 6H 2O+Sunlight \u2192C6H12O6+ 6O 2\n\u00a0 \u00a0 \u00a0 \u00a0Glucose\nMost of the\u00a0decomposition reactions are endothermic.\nCorrosion\nGradual deterioration of a material, usually a metal, by the action of moisture, air or\nchemicals in the surrounding environment.",
  "Corrosion\nGradual deterioration of a material, usually a metal, by the action of moisture, air or\nchemicals in the surrounding environment.\nRusting:\n4Fe(s) + 3O 2(from \u00a0air) +xH 2O(moisture ) \u2192 2Fe 2O3.xH 2O(rust)\nCorrosion of copper:\nCu(s) +H2O(moisture ) +CO 2(from \u00a0air) \u2192CuCO 3.Cu(OH)2(green )\nCorrosion of silver:\nAg(s) +H2S(from \u00a0air) \u2192Ag2S(black) +H2(g)\nRancidity\nIt refers to oxidation of fats and oils in food that is kept for a long time. It gives foul smell\nand bad taste to food. Rancid food causes stomach infection on consumption.\nPrevention:\n(i) Use of air-tight containers(ii) Packaging with nitrogen\n(iii) Refrigeration\n(iv) Addition of antioxidants or preservatives",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS 2.txt\nChemical Reactions & \nequations \nPower Point Presentation END",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nChemical  Reactions  and Equations \nChemical  Reactions  and Equations \nAny process that involves the rearrangement of structure of the substance or conversion of \nreactants into products is defined as  Chemical  Reaction . \nFor a Chemical  Reaction  to occur,  the change  can be observed  in the form  of - \n\uf0b7 Change  in State : Melting of ice into water.  \n\uf0b7 Change  in Colour : Iron rusting which has colour change from silver to reddish brown.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\n\uf0b7 Change  in Temperature : There are two types of reaction i.e  Exothermic and Endothermic \nReaction.  \nExothermic  Reactions:  Those reactions in which energy is released in the form of heat are \ncalled  Exothermic  Reactions . \nExamples  - \n(1) All combustion reactions e.g.  \nCH 4+ 2O 2 \u2014> CO 2 + 2H 2O + Heat \n(2) Thermite reactions e.g. \n2A 1 + Fe 2O3 \u2014> 2Fe + Al 2O3 + Heat \nCombinations are generally exothermic in nature. The decomposition of organic matters into \ncompost is an example of exothermic reaction.  \nEndothermic  Reactions:  Those reactions in which energy is absorbed are called  Endothermic  \nReactions . \nExamples  - \n \nalso,  the reaction  of photosynthesis  -",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nalso,  the reaction  of photosynthesis  - \n \n\uf0b7 Evolution  of any gas: When  Zinc reacts  with sulphuric  acid it gives  hydrogen  gas. \nZn + H2 SO 4 \u2192 ZnSO 4 + H2 \nFormation  of Precipitate : When a soluble carbonate reacts with Barium, Barium Carbonate \nprecipitate can be observed.  \nChange  in State \nSome chemical reactions are characterized by a change in state.  \n\uf0b7 When wax is burned (in the form of wax candle,) then water and carbon dioxide are formed.  \n\uf0b7 Now, wax is a liquid whereas carbon dioxide is a gas. This means that during the combustion \nreaction of wax, the physical state changes from solid to liquid and gas.  \nPhysical  Change \n\uf0b7 In this change identity of the substance remains same.  \n\uf0b7 For Example, Melting, Boiling etc.  \nChemical  Change \n\uf0b7 The identity of the substances change  \n\uf0b7 Reactants are converted into substance due to formation or broken down of older bonds",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nChemical  Equation \nThe symbolic representation of chemical reaction using symbols and formulae is known \nas Chemical  Equation . For this,  reactants are written in left hand side whereas products are \nwritten on the right.  \nBalanced  Chemical  Equation \nA balanced chemical equation is the one where the number of atoms involved in reactants side is \nequal to number of atoms on product side.  \n \nEq.1.  Example  of Balanced  Chemical  Equation \nSteps  to form  Balanced  Equation \nTo show how to balance the equation, the following equation is used - \nFe + H2O \u2192 Fe 3O4 + H2 \nStep  1: First of all, draw the boxes around each formula as shown below -",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nStep  2: Find out the number of atoms of each element.  For Example , on reactant side, 1 for Fe, \n2 H, and 1 O and on product side we have, 3 for Fe, 4 for O and 2 for H.  \nStep  3: Start to balance the equation with the compound having maximum number of atoms. While \nbalancing does not alter the formula of the compound.  \nStep  4: One by one balance each element on reactant and product side.  \n \nStep  5: After balancing number of atoms on both the side of the equation, finally check the \ncorrectness of the balanced equation.  \n \nStep  6: then write the symbols of the physical state of reactants and products as shown below - \n3Fe(s)  + 4H 2O (g) \u2192 Fe 3O4 (s) + 4H 2 (g) \nThis above equation represents the balanced equation.",
  "Balancing  a Redox  Reaction \nThe basic ionic form of the equation is - \nFe2+ + Cr 2O72- \u2192 Fe3+ + Cr3+ \nOxidation half reaction is - \n \nReduction half reaction is -",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nReduction half reaction is - \n \nUse the reduction half method to balance the equation. Balance the atoms in each half of the \nreaction except H and O atoms.  \nCr 2O72- (aq) \u2192 2 Cr3+(aq) \nAdd water molecules as the reaction is taking place in acidic solution. This is to balance the O \natoms and hydrogen ions.  \nCr 2O72- (aq) + 14 H+(aq) \u2192 2 Cr3+(aq) + 7H 2O  (I) \nThen balance the charges in both half reactions.",
  "This is to balance the O \natoms and hydrogen ions.  \nCr 2O72- (aq) + 14 H+(aq) \u2192 2 Cr3+(aq) + 7H 2O  (I) \nThen balance the charges in both half reactions.  \nFe2+(aq) \u2192 Fe3+(aq) + e- \nCr 2O72- (aq) + 14 H+ + 6e- \u2192 2 Cr3+ + 7H 2O \n6 Fe2+(aq) \u2192 6 Fe3+(aq) + 6e- \nTwo half of the equations are added to get the overall reaction  \n6Fe2+(aq) + Cr 2O72-(aq) + 14H+(aq) \u2192 6Fe3+(aq) + 2Cr3+(aq) + 7H 2O (I) \nTypes  of Chemical  Reaction \n\uf0b7 Combination  Reaction  is reaction when single product is  formed from the combination of two \nor more reactants.  For Example -",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nEq.2.  Example  of Combination  Reaction \nReactions can be exothermic as well as endothermic. Exothermic reaction release heats and \nraises the temperature of the surroundings.  For Example , Respiration is an example of exothermic \nreaction.  \n \nEq.3.  Example  of Exothermic  Reaction \nEndothermic reaction involved the absorption of the heat and thus it cools the surrounding. The \ndecomposition of dead organic material is an endothermic reaction.  \n\uf0b7 Decomposition  Reaction  is type of reaction which involves breakdown of single reactant into \nsimpler products. Decomposition of silver chloride into silver and chlorine in presence of \nsunlight is an example of decomposition reaction.  \n \nEq.4.  Example  of Deco mposition  Reaction \n\uf0b7 Displacement  Reaction  is a reaction in which more reactive element will \ndisplaces the less reactive element.",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nEq.4.  Example  of Deco mposition  Reaction \n\uf0b7 Displacement  Reaction  is a reaction in which more reactive element will \ndisplaces the less reactive element.  \n \nEq. 5. Example  of Displacement  Reaction \n\uf0b7 Double  Displacement  Reaction  is a type of reaction in which cations and anions in the \nreactants switch the places to form new products.  \n \nEq. 6. Example  of Double  Displacement  Reaction \n\uf0b7 Redox  Reaction  is also known as  Oxidation -reduction  Reaction . In this type of reaction \ntransfer of electrons occurs between the two species. Oxidation is def ined as addition of oxygen \nor removal of hydrogen. Reduction is defined as removal of oxygen or addition of hydrogen. \nOxidizing agent is the one which gains the electrons and is reduced in a chemical reaction. \nReducing agent is oxidized in a chemical react ion and it loses the electrons. Fluorine is the \nstrongest oxidizing agent. Formic acid is a reducing agent",
  "CHAPTER 1 CHEMICAL REACTIONS AND EQUATIONS5.txt\nEq.7.  Example  of Redox  Reaction \nCorrosion \nMetals are prone to corrosion. It is a slow conversion of metals into some undesirable compounds. \nThis occur may be due to reaction with oxygen, gases, acids etc. When irons reacts with \natmospheric oxygen and moisture, a red layer is formed on the surface of the iron, this process is \nknown as  Rusting . \n \nEq. 8. Equation  for Iron Rusting \nRancidity \nWhen food containing fats and oils are exposed to the atmosphere, the oxidation of fat and oil \noccurs, this is known as  Rancidity . \nMethods  to Prevent  Rancidity \n\uf0b7 Store cooking oils from direct sunlight.  \n\uf0b7 Food should be placed at low temperature.  \n\uf0b7 By adding antioxidants food can be protected from rancidity.  \n\uf0b7 Packing material should replace the air with nitrogen.  \n\uf0b7 Minimize the use of salts in fried foods."
]