CLASS 10 SCIENCE
COMPLETE QUESTION BANK
All 13 Chapters | 300 Questions Each | 3,900 Total Questions
English Medium | 5 Levels | Copyright Free | Original Questions
, CHAPTER 1: CHEMICAL REACTIONS & EQUATIONS
Total: 283 Questions
🟢 Level 1 – Basic Understanding
Q1. What is a chemical reaction?
Q2. Define reactants and products in a chemical equation.
Q3. What is a chemical equation?
Q4. What does the arrow (→) represent in a chemical equation?
Q5. What is a balanced chemical equation?
Q6. State the law of conservation of mass.
Q7. What is a combination reaction? Give one example.
Q8. What is a decomposition reaction? Give one example.
Q9. What is a displacement reaction? Give one example.
Q10. What is a double displacement reaction? Give one example.
Q11. Define oxidation in terms of oxygen.
Q12. Define reduction in terms of oxygen.
Q13. What is a redox reaction?
Q14. What is an exothermic reaction? Give one example.
Q15. What is an endothermic reaction? Give one example.
Q16. What is corrosion? Give one example.
Q17. What is rancidity?
Q18. What are state symbols in chemical equations? List all four.
Q19. What does the symbol (aq) mean in a chemical equation?
Q20. What is a precipitate?
Q21. What is a precipitation reaction? Give one example.
Q22. What is the role of a catalyst in a chemical reaction?
Q23. What is thermal decomposition? Give one example.
Q24. What is photolysis? Give one example.
Q25. What is electrolysis? Give one example.
Q26. Write the chemical formula of water.
Q27. Write the chemical formula of carbon dioxide.
Q28. Write the chemical formula of calcium carbonate.
Q29. What is rust? Write its chemical formula.
, Q30. What is quick lime? Write its formula.
Q31. What is slaked lime? Write its formula.
Q32. Write the formula of sodium hydroxide.
Q33. Write the formula of hydrogen gas.
Q34. What does Δ above an arrow indicate in a chemical equation?
Q35. What gas is produced when zinc reacts with dilute sulphuric acid?
Q36. What happens when magnesium burns in oxygen?
Q37. What is the colour of copper sulphate solution?
Q38. What colour change occurs when iron nails are placed in copper sulphate solution?
Q39. What is the colour of ferrous sulphate solution?
Q40. Name one reaction used in black-and-white photography.
Q41. What gas is evolved when HCl reacts with Na₂CO₃?
Q42. What is a skeletal chemical equation?
Q43. What happens when CO₂ is passed into lime water?
Q44. Write the formula of barium sulphate.
Q45. Name one application of exothermic reactions in daily life.
Q46. Write the formula of calcium oxide.
Q47. Write the formula of ferrous sulphate.
Q48. Name the type of reaction that occurs during burning of wood.
Q49. What is a neutralisation reaction? Give one example.
Q50. Write the formula of nitric acid.
Q51. What does hν above an arrow represent?
Q52. Write the formula of sodium carbonate.
Q53. Name one reducing agent commonly used in lab reactions.
Q54. Name one oxidising agent commonly used in lab reactions.
Q55. What is the general word equation for respiration?
Q56. Write the formula of methane.
Q57. What is the formula of zinc sulphate?
Q58. Define a chemical change.
Q59. What type of reaction is burning of magnesium in air?
Q60. Name the gas produced when sodium reacts with water.
Q61. What is the formula of calcium chloride?
Q62. What is the formula of iron(III) oxide?
🔵 Level 2 – Concept Clarity
, Q63. Why must a chemical equation be balanced?
Q64. Explain why corrosion is a chemical change and not a physical change.
Q65. Why does the colour of copper sulphate solution change when iron is added?
Q66. Explain the difference between a combination and a decomposition reaction.
Q67. Why is respiration classified as an exothermic reaction?
Q68. Why is photosynthesis classified as an endothermic reaction?
Q69. How is a displacement reaction different from a double displacement reaction?
Q70. Explain why silver chloride turns grey when exposed to sunlight.
Q71. Why do antioxidants prevent rancidity in food?
Q72. Why are chips packets filled with nitrogen gas instead of air?
Q73. Explain with an example how reduction and oxidation always occur together.
Q74. Why does quick lime produce heat when added to water?
Q75. How does electrolysis of water prove that water is a compound of H and O?
Q76. Explain the significance of state symbols in chemical equations.
Q77. Why is a catalyst not consumed in a reaction even though it speeds it up?
Q78. Why does magnesium burn vigorously in oxygen but iron does not?
Q79. Explain the difference between a physical and a chemical change with examples.
Q80. Why does precipitation occur in a double displacement reaction?
Q81. How does temperature affect the rate of a chemical reaction?
Q82. Explain why rancidity occurs faster in warm climates.
Q83. Explain why excess CO₂ dissolves a CaCO₃ precipitate in lime water.
Q84. Explain the difference between oxidising agent and reducing agent.
Q85. Why do metallic objects corrode faster in coastal, salty, humid areas?
Q86. Explain why the reaction of zinc with dilute H₂SO₄ is a displacement reaction.
Q87. Explain what happens when ferrous sulphate crystals are heated strongly.
Q88. Why can we not balance an equation by changing subscripts of formulas?
Q89. Explain why incomplete combustion produces CO instead of CO₂.
Q90. What is the difference between an oxidising agent and a substance that is oxidised?
Q91. Why does copper turn green on prolonged exposure to moist air?
Q92. Explain how corrosion of aluminium differs from corrosion of iron.
Q93. Why does the rate of a reaction decrease as the reaction proceeds?
Q94. Why do reactions require activation energy to start?
Q95. Explain the concept of a reducing agent using the example of H₂ reducing CuO.
Q96. Why is the decomposition of H₂O₂ classified as a decomposition reaction?
Q97. How does Na₂SO₄ + BaCl₂ reaction confirm a double displacement reaction?
COMPLETE QUESTION BANK
All 13 Chapters | 300 Questions Each | 3,900 Total Questions
English Medium | 5 Levels | Copyright Free | Original Questions
, CHAPTER 1: CHEMICAL REACTIONS & EQUATIONS
Total: 283 Questions
🟢 Level 1 – Basic Understanding
Q1. What is a chemical reaction?
Q2. Define reactants and products in a chemical equation.
Q3. What is a chemical equation?
Q4. What does the arrow (→) represent in a chemical equation?
Q5. What is a balanced chemical equation?
Q6. State the law of conservation of mass.
Q7. What is a combination reaction? Give one example.
Q8. What is a decomposition reaction? Give one example.
Q9. What is a displacement reaction? Give one example.
Q10. What is a double displacement reaction? Give one example.
Q11. Define oxidation in terms of oxygen.
Q12. Define reduction in terms of oxygen.
Q13. What is a redox reaction?
Q14. What is an exothermic reaction? Give one example.
Q15. What is an endothermic reaction? Give one example.
Q16. What is corrosion? Give one example.
Q17. What is rancidity?
Q18. What are state symbols in chemical equations? List all four.
Q19. What does the symbol (aq) mean in a chemical equation?
Q20. What is a precipitate?
Q21. What is a precipitation reaction? Give one example.
Q22. What is the role of a catalyst in a chemical reaction?
Q23. What is thermal decomposition? Give one example.
Q24. What is photolysis? Give one example.
Q25. What is electrolysis? Give one example.
Q26. Write the chemical formula of water.
Q27. Write the chemical formula of carbon dioxide.
Q28. Write the chemical formula of calcium carbonate.
Q29. What is rust? Write its chemical formula.
, Q30. What is quick lime? Write its formula.
Q31. What is slaked lime? Write its formula.
Q32. Write the formula of sodium hydroxide.
Q33. Write the formula of hydrogen gas.
Q34. What does Δ above an arrow indicate in a chemical equation?
Q35. What gas is produced when zinc reacts with dilute sulphuric acid?
Q36. What happens when magnesium burns in oxygen?
Q37. What is the colour of copper sulphate solution?
Q38. What colour change occurs when iron nails are placed in copper sulphate solution?
Q39. What is the colour of ferrous sulphate solution?
Q40. Name one reaction used in black-and-white photography.
Q41. What gas is evolved when HCl reacts with Na₂CO₃?
Q42. What is a skeletal chemical equation?
Q43. What happens when CO₂ is passed into lime water?
Q44. Write the formula of barium sulphate.
Q45. Name one application of exothermic reactions in daily life.
Q46. Write the formula of calcium oxide.
Q47. Write the formula of ferrous sulphate.
Q48. Name the type of reaction that occurs during burning of wood.
Q49. What is a neutralisation reaction? Give one example.
Q50. Write the formula of nitric acid.
Q51. What does hν above an arrow represent?
Q52. Write the formula of sodium carbonate.
Q53. Name one reducing agent commonly used in lab reactions.
Q54. Name one oxidising agent commonly used in lab reactions.
Q55. What is the general word equation for respiration?
Q56. Write the formula of methane.
Q57. What is the formula of zinc sulphate?
Q58. Define a chemical change.
Q59. What type of reaction is burning of magnesium in air?
Q60. Name the gas produced when sodium reacts with water.
Q61. What is the formula of calcium chloride?
Q62. What is the formula of iron(III) oxide?
🔵 Level 2 – Concept Clarity
, Q63. Why must a chemical equation be balanced?
Q64. Explain why corrosion is a chemical change and not a physical change.
Q65. Why does the colour of copper sulphate solution change when iron is added?
Q66. Explain the difference between a combination and a decomposition reaction.
Q67. Why is respiration classified as an exothermic reaction?
Q68. Why is photosynthesis classified as an endothermic reaction?
Q69. How is a displacement reaction different from a double displacement reaction?
Q70. Explain why silver chloride turns grey when exposed to sunlight.
Q71. Why do antioxidants prevent rancidity in food?
Q72. Why are chips packets filled with nitrogen gas instead of air?
Q73. Explain with an example how reduction and oxidation always occur together.
Q74. Why does quick lime produce heat when added to water?
Q75. How does electrolysis of water prove that water is a compound of H and O?
Q76. Explain the significance of state symbols in chemical equations.
Q77. Why is a catalyst not consumed in a reaction even though it speeds it up?
Q78. Why does magnesium burn vigorously in oxygen but iron does not?
Q79. Explain the difference between a physical and a chemical change with examples.
Q80. Why does precipitation occur in a double displacement reaction?
Q81. How does temperature affect the rate of a chemical reaction?
Q82. Explain why rancidity occurs faster in warm climates.
Q83. Explain why excess CO₂ dissolves a CaCO₃ precipitate in lime water.
Q84. Explain the difference between oxidising agent and reducing agent.
Q85. Why do metallic objects corrode faster in coastal, salty, humid areas?
Q86. Explain why the reaction of zinc with dilute H₂SO₄ is a displacement reaction.
Q87. Explain what happens when ferrous sulphate crystals are heated strongly.
Q88. Why can we not balance an equation by changing subscripts of formulas?
Q89. Explain why incomplete combustion produces CO instead of CO₂.
Q90. What is the difference between an oxidising agent and a substance that is oxidised?
Q91. Why does copper turn green on prolonged exposure to moist air?
Q92. Explain how corrosion of aluminium differs from corrosion of iron.
Q93. Why does the rate of a reaction decrease as the reaction proceeds?
Q94. Why do reactions require activation energy to start?
Q95. Explain the concept of a reducing agent using the example of H₂ reducing CuO.
Q96. Why is the decomposition of H₂O₂ classified as a decomposition reaction?
Q97. How does Na₂SO₄ + BaCl₂ reaction confirm a double displacement reaction?
