Chemical Reactions and Equations

MCQs: 2

Question: 11: Which of the following is termed as exothermic reaction?

1. Reaction in which heat is evolved
2. Reaction in which heat is absorbed
3. Reaction in which there is loss of oxygen
4. Reaction in which there is gain of hydrogen

Answer: (a) Reaction in which heat is evolved

Question: 12: Which of the following is termed as endothermic reaction?

1. Reaction in which heat is evolved
2. Reaction in which heat is absorbed
3. Reaction in which there is loss of oxygen
4. Reaction in which there is gain of hydrogen

Answer: (b) Reaction in which heat is absorbed

Question: 13: What is the name of reaction which decomposes after supply of heat?

1. Combination reaction
2. Thermal decomposition
3. Displacement reaction
4. Redox reaction

Answer: (b) Thermal decomposition

Question: 14: What is the name of reaction in which both oxidation and reduction takes place?

1. Combination reaction
2. Thermal decomposition
3. Displacement reaction
4. Redox reaction

Answer: (d) Redox reaction

Question: 15: What is the name of substance which does get deposited over iron because of moisture present in air?

1. Sulphide
2. Rust
3. Carbonate
4. Oxygen

Answer: (b) Rust

Question: 16. Why magnesium ribbon is cleaned before burning?

1. To remove dust
2. To remove magnesium oxide
3. To remove ribbon oxide
4. All of the above

Answer: (b) To remove magnesium oxide

Question: 17. On the basis of evolution or absorption of heat, chemical reactions can be divided in how many types?

1. Two
2. Three
3. Four
4. One

Answer: Two

Question: 18. Which of the following gas is produced when carbon is burnt in air?

1. Carbon dioxide
2. Sulphur dioxide
3. Oxygen
4. Hydrogen

Answer: (a) Carbon dioxide

Question: 19. Which of the following gives energy while respiration?

1. Burning of coal
2. Burning of natural gas
3. Burning of oxygen
4. Burning of glucose

Answer: (d) Burning of glucose

Question: 20. What happens when hydrogen reacts with oxygen?

1. Carbon dioxide is formed
2. Water is formed
3. Hydrogen carbonate is formed
4. All of the above

Answer: (b) Water is formed