Chemical Reactions and Equations Class 10 MCQs with Answers
Chemical Reactions and Equations – Class 10 MCQs with Answers
Class: 10 | Subject: Science
Section: Chemistry
Based on: NCERT Syllabus | CBSE Board Examination
1. What is a chemical reaction?
Answer: B
Explanation: A chemical reaction results in the formation of one or more new substances with different properties.
Explanation: A chemical reaction results in the formation of one or more new substances with different properties.
2. Rusting of iron is which type of reaction?
Answer: D
Explanation: Rusting involves oxidation of iron and reduction of oxygen, hence it is a redox reaction.
Explanation: Rusting involves oxidation of iron and reduction of oxygen, hence it is a redox reaction.
3. Mg + O₂ → MgO is a:
Answer: B
Explanation: Two substances combine to form a single product.
Explanation: Two substances combine to form a single product.
4. Which gas is released when zinc reacts with HCl?
Answer: B
Explanation: Zn + 2HCl → ZnCl₂ + H₂. Hydrogen gas is evolved.
Explanation: Zn + 2HCl → ZnCl₂ + H₂. Hydrogen gas is evolved.
5. Balanced equation obeys:
Answer: B
Explanation: Total mass of reactants equals total mass of products.
Explanation: Total mass of reactants equals total mass of products.
6. Decomposition reactions require:
Answer: B
Energy like heat/light breaks compounds.
Energy like heat/light breaks compounds.
7. CaCO₃ → CaO + CO₂ is:
Answer: B
Single compound breaks into simpler substances.
Single compound breaks into simpler substances.
8. Reaction releasing heat:
Answer: B
Heat is produced during exothermic reactions.
Heat is produced during exothermic reactions.
9. White precipitate forms in:
Answer: A
AgCl white ppt forms.
AgCl white ppt forms.
10. Oxidation means:
Answer: C
Oxidation = gain of oxygen/loss of electrons.
Oxidation = gain of oxygen/loss of electrons.
11. Reduction means:
Answer: B
Reduction is removal of oxygen or gain of electrons.
Reduction is removal of oxygen or gain of electrons.
12. Displacement occurs when:
Answer: B
More reactive metal displaces less reactive.
More reactive metal displaces less reactive.
13. Electrolysis of water gives:
Answer: C
Water decomposes into hydrogen and oxygen.
Water decomposes into hydrogen and oxygen.
14. Rancidity is prevented by:
Answer: B
Antioxidants prevent oxidation of fats.
Antioxidants prevent oxidation of fats.
15. Respiration is:
Answer: B
Glucose oxidation releases energy.
Glucose oxidation releases energy.
16. Blue vitriol is:
Answer: A
Hydrated copper sulphate crystals.
Hydrated copper sulphate crystals.
17. Corrosion is:
Answer: B
Metals react with environment.
Metals react with environment.
18. Quicklime formula:
Answer: B
Formed by heating limestone.
Formed by heating limestone.
19. Neutralization forms:
Answer: A
Acid + Base → Salt + Water.
Acid + Base → Salt + Water.
20. Skeletal equation is:
Answer: B
Unbalanced representation of reaction.
Unbalanced representation of reaction.