Class 10 Science MCQ Chapter 1 Chemical Reaction and Equation, Class 10 Science MCQ Question Answer, Class 10 Science Multiple Choice Question Answer to each chapter is provided in the list of SCERT Science Class 10 Objective Types Question Answer so that you can easily browse through different chapters and select needs one. Class 10 Science MCQ Chapter 1 Chemical Reaction and Equation Question Answer can be of great value to excel in the examination.
SCERT Class 10 Science MCQ Chapter 1 Chemical Reaction and Equation
SCERT Class 10 General Science MCQ Chapter 1 Chemical Reaction and Equation Notes covers all the exercise questions in SCERT Science Textbooks. The NCERT Class 10 Science MCQ Chapter 1 Chemical Reaction and Equation provided here ensures a smooth and easy understanding of all the concepts. Understand the concepts behind every chapter and score well in the board exams.
Chemical Reaction and Equation
Chapter – 1
Multiple Choice Questions & Answers
1. Electrolysis of water is an example of-
(a) Combination reaction.
(b) Decomposition reaction.
(c) Displacement reaction.
(d) Exothermic reaction.
Ans: (b) Decomposition reaction.
2. In which of the following reactions, there is an exchange of ions between the reactants-
(a) Displacement.
(b) Decomposition.
(c) Double displacement.
(d) Combination.
Ans: (c) Double displacement.
3. Burning of natural gas is an example of-
(a) Endothermic reaction.
(b) Exothermic reaction.
(c) Combination reaction.
(d) Decomposition reaction.
Ans: (b) Exothermic reaction.
4. ZnO + C→ Zn + CO – The substances that are oxidised and reduced in the following reaction are respectively-
(a) ZnO, C
(b) Zn, CO
(c) ZnO, CO
(d) C, ZnO
Ans: (d) C, ZnO
5. MnO₂+ 4HCI → MnCl₂ + 2H₂O + Cl₂ — The substances that are oxidised and reduced in the following reaction are respectively-
(a) HCI, MnO₂
(b) HCI, MnCl₂
(c) MnO₂, HCI
(d) MnO₂, Cl₂
Ans: (a) HCI, MnO₂
6. The white powder produced when a magnesium ribbon is burnt in air is-
(a) Magnesium Carbonate
(b) Magnesium Nitrate.
(c) Magnesium Oxide.
(d) Magnesium hydroxide.
Ans: (c) Magnesium Oxide.
7. The reaction between quick lime and water is an example of –
(a) Combination reaction.
(b) Decomposition reaction.
(c) Exothermic reaction.
(d) (a) and (c).
Ans: (d) (a) and (c).
8. Thermal decomposition of ferrous sulphate gives-
(a) SO₂
(b) SO₃
(c) Fe₂ O₃
(d) All of above.
Ans: (d) All of above.
9. Production of quick lime by heating limestone is an example of-
(a) Combination reaction.
(b) Decomposition reaction.
(c) Displacement reaction.
(d) Exothermic reaction.
Ans: (b) Decomposition reaction.
10. Which one is not formed in the thermal decomposition of lead nitrate-
(a) PbO
(b) NO₂
(c) N₂
(d) O₂
Ans: (c) N₂
11. Conversion of silver chloride to silver in the sunlight is an example of-
(a) Decomposition reaction.
(b) Combination reaction.
(c) Endothermic reaction.
(d) (a) and (c).
Ans: (d) (a) and (c).
12. Reaction between copper sulphate and Zinc is an example of-
(a) Displacement reaction.
(b) Precipitation reaction.
(c) Double displacement reaction.
(d) Combination reaction.
Ans: (a) Displacement reaction.
13. BaCl₂ + H₂ SO₄ → BaSO₄ + 2HCl –The above reaction is an example of-
(a) Displacement reaction.
(b) Double Displacement reaction.
(c) Precipitation reaction.
(d) (b) and (c).
Ans: (d) (b) and (c).
14. 2Cu+0₂ → 2CuO – The substances that are oxidised and reduced in the above reaction-
(a) CuO, O₂
(b) Cu, O₂
(c) O₂, CuO
(d) Cu, CuO
Ans: (b) Cu, O₂
15. The colour of coating formel an copper due to its corrosion is-
(a) Black.
(b) Brown.
(c) Green.
(d) Red.
Ans: (c) Green.
16. The colour of coating formed on silver due to its corrosion is-
(a) Black.
(b) Green.
(c) Brown.
(d) Grey.
Ans: (a) Black.
17. A magnesium ribbon should be cleaned before burning in air-
(a) To remove dirt.
(b) To make it hot by the friction.
(c) To remove the layer of oxide on its surface.
(d) To remove the layer of hydroxide on its surface.
Ans: (c) To remove the layer of oxide on its surface.
18. Which one of the following is a thermal decomposition reaction?
(a) 2AgCl → 2Ag + Cl₂
(b) 2H₂O→ 2H₂ +O₂
(c) 2AgBr→ 2Ag +Br₂
(d) CaCO₃ → CaO +CO₂
Ans: (d) CaCO₃ → CaO +CO₂
19. The basis of balancing a skeletal equation is-
(a) Law of conservation of energy.
(b) Law of constant proportion.
(c) Law of conservation of mass.
(d) None of above.
Ans: (c) Law of conservation of mass.
20. In the balanced chemical equation x Pb (NO₃)₂ → yPbO + z NO₂ + O₂ the values of x, y and z are respectively.
(a) 2, 3, 4
(b) 2, 2, 4
(c) 2, 2, 2
(d) 3, 2, 4
Ans: (b) 2, 2, 4
21. When water is added to calcium oxide-
(i) Temperature of the mixture increases.
(ii) Temperature of the mixture remains same.
(iii) Calcium hydroxide is produced.
(iv) An endothermic reaction takes place.
The correct option is-
(a) (i), (iii)
(b) (ii), (iii)
(c) (i), (iii), (iv)
(d) only (iv)
Ans: (a) (i), (iii)
22. When solutions of sodium sulphate and barium chloride are mixed-
(i) Sodium chloride and barium sulphate are produced.
(ii) A displacement reaction occurs.
(iii) A double displacement reaction occurs.
(iv) A precipitation reaction occurs.
The correct option is-
(a) (i), (ii), (iii)
(b) (i), (ii)
(c) (i), (iii)
(d) (i), (iii), (iv)
Ans: (d) (i), (iii), (iv)
23. Which of the following is not a combination reaction?
(a) CaO + H₂ O → Ca(OH)₂
(b) C+O₂ → CO₂
(c) CH₄+ 2O₂ → CO₂ + 2H₂ O
(d) 2H₂ + O₂ → 2H₂O
Ans: (c) CH₄+ 2O₂ → CO₂ + 2H₂ O
24. The brown fumes emitted when lead nitrate is heated are-
(a) NO₂
(b) PbO
(c) O₂
(d) Pb
Ans: (a) NO₂
25. The colour of white silver chloride after placing it in the sunlight for some time will be-
(a) White.
(b) Red.
(c) Grey.
(d) Yellow.
Ans: (c) Grey.
26. Which one of the following reactions is used in black and white photography?
(a) Fe + CuSO₄ → FeSO₄+ Cu
(b) 2AgBr→ 2Ag₂ + Br₂
(c) 2H₂O→ 2H₂+ O₂
(d) 2Pb (NO₃)₂ →2PbO + 4NO₂ + O₂
Ans: (b) 2AgBr→ 2Ag₂ + Br₂
27. Which of the statements about the reaction below are incorrect?
2PbO + C → 2Pb + CO₂
(i) Lead is getting reduced.
(ii) Carbon dioxide is getting oxidised.
(iii) Carbon is getting oxidised.
(iv) Lead oxide is getting reduced.
(a) (i) and (iii)
(b) (i) and (iii)
(c) (i), (ii) and (iii)
(d) All
Ans: (a) (i) and (iii)
28. Fe₂ O₃ +2AI→ Al₂ O₃ + 2Fe
The above reaction is an example of a-
(a) Combination reaction.
(b) Double displacement reaction.
(c) Decomposition reaction.
(d) Displacement reaction.
Ans: (d) Displacement reaction.
29. What happens when dilute hydrochloric acid is added to iron fillings?
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Ans : (a) Hydrogen gas and iron chloride are produced.
30. Which of the following is a characteristic of a chemical reaction?
(a) Change in state.
(b) Change in colour.
(c) Evolution of a gas.
(d) All of the above.
Ans: (d) All of the above.
Very Short & Short Type Questions and Answers:
1. What is a chemical reaction?
Ans : When a chemical change occurs in a substance, a chemical reaction is said to be taken place.
2. What is a chemical equation?
Ans : The way of representing a chemical reaction with the help of the symbols and formulae of the elements and compounds respectively taking part in the reaction is called a chemical equation.
3. What is an unbalanced or skeletal equation?
Ans : When the number of atoms of each element on either side of the equation is not equal, then such a chemical equation is called an unbalanced or skeletal equation.
4. What is a balanced chemical equation?
Ans : When the number of atoms of each element on either side of a chemical equation is equal, then it is called a balanced chemical equation.
5. Name the white coloured substance produced when a magnesium ribbon is burnt in air. Mention the balanced chemical equation for the reaction involved.
Ans: Magnesium oxide (MgO)
2Mg+O₂ → 2MgO
6. Is a combination reaction?
Ans : The chemical reaction in which two or more reactants combine to form a single product is called a combination reaction.
7. Give example of a combination reaction.
Ans: C+O₂ → CO₂
8. Calcium oxide reacts vigorously with water to form slaked lime. Write a balanced equation for the reaction and mention the type of reaction.
Ans: CaO +H₂O→ Ca(OH₂)+ Heat Type of reaction: combination.
9. What is a decomposition reaction?
Ans : The chemical reaction in which a reactant breaks down to form two or more simple products is called a decomposition reaction.
10. Give example of a decomposition reaction.
Ans:
11. Give example of a chemical reaction used in black and white photography.
Ans:
12. Name the substances produced due to electrolysis of water. Write the balanced chemical equation for this process. Name the type of reaction.
Ans:
13. What is a thermal decomposition reaction?
Ans : A decomposition reaction in which a single reactant breaks down into two or more simple products by absorbing heat energy is called a thermal decomposition reaction.
14. Give example of a thermal decomposition reaction.
Ans:
15. What is a displacement reaction?
Ans : The chemical reaction in which a more reactive element displaces a less reactive element from its compounds is called a displacement reaction.
16. Give example of a displacement reaction.
Ans: Fe + CuSO₄ → FeSO₄ + Cu
17. What is a double displacement reaction?
Ans : A chemical reaction in which there is an exchange of ions between the reactants to form the products in called a double displacement reaction.
18. Give example of a double displacement reaction.
Ans: Na₂SO₄ + → BaCl₂ → BaSO₄ + 2NaCl
19. What is an oxidation reaction?
Ans: A chemical reaction in which a substance gains oxygen or loses hydrogen is called an oxidation reaction.
20. Give example of an oxidation reaction.
Ans:
21. What is a reduction reaction?
Ans: A chemical reaction in which a substance gains hydrogen or loses oxygen is called a reduction reaction.
22. Give example of a reduction reaction.
Ans:
23. What is an oxidation reduction or redox reaction?
Ans : A chemical reaction in which a substance gets reduced, while the other substance gets oxidised at the same time is called an oxidation-reduction or redox reaction.
24. Give example of a redox reaction.
Ans:
25. What do you mean by corrosion?
Ans: When a substance is attacked by substances around it such as moisture, acids etc., then it is said to corrode and this process is called corrosion.
26. What is rancidity?
Ans: When fats and oils are oxidised, their smell and taste change and this phenomenon is called rancidity.
27. Take lead nitrate solution in a test tube and add a solution of potassium iodide to it. What will you observe?
Ans: A yellow-coloured precipitate will be observed in the test tube.
28. Write the reaction which takes place when a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube.
Ans: Pb(NO₃)₂ + 2 KI → PbI₂ + 2KNO₃
29. Write the reaction that takes place when you take some zinc granules in a test tube and add dilute sulphuric acid to it.
Ans : Zn+H₂SO₄ → ZnSO₄ + H₂
30. When you take some zinc granules in a test tube and add dilute sulphuric acid to it, formation of bubbles will be observed in the test tube. Of which gas are these bubbles?
Ans: Hydrogen.
31. How will the colour of ferrous sulphate crystals change if they are heated in a dry boiling tube?
Ans: The green colour of the ferrous sul- phate crystals will change to white.
32. Name the substances that are produced by the decomposition of ferrous sulphate when some ferrous sulphate crystals are heated in a boiling tube.
Ans: Ferric oxide, sulphur dioxide and sulphur trioxide.
33. Write the reaction that takes place when crystals of ferrous sulphate are heated.
Ans:
34. When lead nitrate powder is heated in a boiling tube, a brown-coloured gas will be seen to be emitted. Identify the gas.
Ans : Nitrogen dioxide.
35. Which substances are produced when lead nitrate is decomposed?
Ans: Lead oxide, nitrogen dioxide and oxygen.
36. Write the chemical reaction that takes place when lead nitrate powder is heated.
Ans: 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
37. Why does the blue colour of copper sulphate solution change when iron nails are dipped in it?
Ans: Due to formation of ferrous sulphate.
38. Why does the colour of iron nails become brown when they are dipped in a solution of copper sulphate?
Ans: Due to the deposition of copper metal produced in the reaction on the surfaces of iron nails.
39. Write the reaction that takes place when iron nails are dipped in a solution of copper sulphate.
Ans: Fe + CuSO₄ → FeSO₄ + Cu
40. Take about 2g silver chloride in a china dish and place it in sunlight for some time. What will be the colour of silver chloride?
Ans: Grey.
41. Write a balanced chemical equation for the reaction that takes place in silver chloride when placed is sunlight.
Ans:
42. What will happen if you place some yellow- coloured silver bromide in a china dish in the sunlight for some time?
Ans: Silver and bromine will be produced due to the decomposition of silver bromide by light.
43. Write the chemical equation for the reaction that takes place in silver bromide in the sunlight.
Ans:
44. Why are a few drops of dilute sulphuric acid added to the water in the of electrolysis of water?
Ans: Because pure water is a poor conduction of electricity. So the ions of acid help in the conduction of electricity through water.
45. Take about 3mL of sodium sulphate solution in a test tube and add about 3mL of barium chloride solution to it. What will you observe?
Ans: A white precipitate will be seen to be formed.
46. Write the balanced chemical equation for the reaction that takes place when barium chloride solution is added to a solution of sodium sulphate.
Ans: Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl
47. Take about 1g of copper powder in a china dish and heat it. What will be the colour of copper powder.
Ans: Black.
48. Write the reaction that takes place when copper powder is heated in a china dish.
Ans:
49. Give an example of corrosion of metal.
Ans: Rusting of iron articles.
50. What happens when limestone is heated?
Ans: Quick lime and carbon dioxide are produced by the decomposition of limestone.
51. Write the chemical reaction that takes place when limestone is heated.
Ans:
52. Write the chemical reaction involved with the electrolysis of water.
Ans:
53. What happens when natural gas is burnt?
Ans: Carbon dioxide and water are produced along with the release of a large amount of heat and light energy.
54. Write the chemical reaction that takes place when natural gas is burnt in air.
Ans : CH₄ + 2O₂ → CO₂ + 2H₂O + heat and light.
55. Why should a magnesium ribbon be cleaned before burning in air?
Ans: At normal temperature magnesium reacts with oxygen in air to form a thin layer of magnesium oxide. This protective oxide layer prevents magnesium from getting oxidised further. So, we should clean a magnesium ribbon before burning in air.
56. Write a balanced chemical equation with state symbols for the following reactions.
(i) Solutions of barium chloride and sodium in water react to give insoluble barium sulphate and the solution of sodium chloride.
(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.
Ans : (i) BaCl ₂ (aq) + Na ₂SO₄ (aq) → BaSO₄ (s) + 2NaCl (aq)
(ii) NaOH(aq) + HCl(aq) → NaCl (aq) + H₂ O(l).
57. A solution of a substance ‘X’ is used for the white washing. Name the substance ‘X’ and write its formula.
Ans: Calcium oxide, CaO.
58. Identify the substances that are oxidised and the substances that are reduced in the following reactions.
(i) 4Na (s) + O₂(g) → 2Na₂ O(s)
(ii) CuO(s) + H₂ (g) → Cu(s)
Ans: (i) Substance oxidised: Na, Substance reduced: O₂
(ii) Substance oxidised: H₂ Substance reduced: CuO
59. Write one equation each for decomposition reactions that use energy in the form of heat, light and electricity
Ans:
60. In the refining of silver, the recovery of silver from silver nitrate solution d involved displacement by copper metal. Write down the reaction involved.
Ans : Cu + 2AgNO₃ → Cu (NO₃)₂ + 2Ag
61. Why do we apply paint on iron articles?
Ans: Iron reacts with oxygen and water vapour present in the air and produces rust and thus gets corroded. So, to prevent iron from coming in contact with moist air, we apply paint on iron articles.
62. Oil and fat containing food items are flushed with nitrogen. Why?
Ans: Because, nitrogen is an antioxidant, which prevents food items containing oil and fats from getting oxidised and thus protects them from getting rancid.
