Chemical Reactions and Equations - Class 10th Science

MCQs: 4

Question: 31. What happens when silver bromide is exposed to sunlight?

  1. Hydrogen gas is formed
  2. Bromine gas is formed
  3. Chlorine gas is formed
  4. Iodine gas is formed

Answer: (b) Bromine gas is formed

Question: 32. Which metal is displaced when lead is put in the solution of copper chloride?

  1. Lead
  2. Copper
  3. Chlorine
  4. All of the above.

Answer: (b) Copper

Question: 33. Which of the following is formed when lead metal reacts with the solution of copper chloride?

  1. No reaction takes place
  2. Copper chlorine
  3. Lead chloride
  4. Copper-lead chloride

Answer: (c) Lead chloride

Question: 34. Which metal is displaced when zinc metal is put in the solution of copper sulphate?

  1. Copper
  2. Zinc
  3. Sulphate
  4. All of the above

Answer: (a) Copper

Question: 35. What happens when sodium sulphate solution is mixed with the solution of barium chloride?

  1. Barium sulphate is formed
  2. Sodium sulphate is formed
  3. Sulphur dioxide gas is formed
  4. No reaction takes place

Answer: (a) Barium sulphate is formed

Question: 36. What happens when Copper metal is dipped in the solution of zinc sulphate?

  1. Copper sulphate is formed
  2. Oxygen gas is formed
  3. Zinc metal is separated
  4. No reaction takes place

Answer: (d) No reaction takes place

Explanation: Copper is less reactive than zinc, hence no reaction takes place.

Question: 37. What happens when zinc metal is dipped in the solution of copper sulphate?

  1. Zinc sulphate is formed
  2. Zinc oxide is formed
  3. Zinc sulphide is formed
  4. No reaction takes place

Answer: (a) Zinc sulphate is formed

Question: 38. Why are articles made of iron painted to prevent rust?

  1. Paint makes articles made of iron beautiful
  2. Paint prevents iron articles to come in contact with moisture present in air.
  3. Paint prevents iron articles to getting sticky
  4. All of the above

Answer: (b) Paint prevents iron articles to come in contact with moisture present in air.

Question: 39. Which of the following is termed as rancidity?

  1. Reduction of oxygen present in food
  2. Oxidation of oil present in food
  3. Oxidation of sugar present in food
  4. All of the above

Answer: (b) Oxidation of oil present in food

Question: 40. How rancidity can be prevented?

  1. By adding antioxidants in food
  2. By adding more oxygen to food
  3. By keeping food items in open
  4. All of the above

Answer: (a) By adding antioxidants in food

MCQs Test