Chemical Reactions and Equations
MCQs: 4
Question: 31. What happens when silver bromide is exposed to sunlight?
- Hydrogen gas is formed
- Bromine gas is formed
- Chlorine gas is formed
- 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?
- Lead
- Copper
- Chlorine
- 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?
- No reaction takes place
- Copper chlorine
- Lead chloride
- Copper-lead chloride
Answer: (c) Lead chloride
Question: 34. Which metal is displaced when zinc metal is put in the solution of copper sulphate?
- Copper
- Zinc
- Sulphate
- All of the above
Answer: (a) Copper
Question: 35. What happens when sodium sulphate solution is mixed with the solution of barium chloride?
- Barium sulphate is formed
- Sodium sulphate is formed
- Sulphur dioxide gas is formed
- 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?
- Copper sulphate is formed
- Oxygen gas is formed
- Zinc metal is separated
- 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?
- Zinc sulphate is formed
- Zinc oxide is formed
- Zinc sulphide is formed
- No reaction takes place
Answer: (a) Zinc sulphate is formed
Question: 38. Why are articles made of iron painted to prevent rust?
- Paint makes articles made of iron beautiful
- Paint prevents iron articles to come in contact with moisture present in air.
- Paint prevents iron articles to getting sticky
- 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?
- Reduction of oxygen present in food
- Oxidation of oil present in food
- Oxidation of sugar present in food
- All of the above
Answer: (b) Oxidation of oil present in food
Question: 40. How rancidity can be prevented?
- By adding antioxidants in food
- By adding more oxygen to food
- By keeping food items in open
- All of the above
Answer: (a) By adding antioxidants in food
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