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Chemistry Past Questions and Answers

Jamb Chemistry Questions

Question 26:

Which of the following does NOT happen when a zinc rod is introduced into a solution of copper (ll) sulphate?

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A Electrons flow towards the zinc rod
B The zinc rod dissolves
C The temperature of the soil changes
D The blue colour of the solution gradually disappears
E Copper metal is deposited

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Question 27:

Hardening of an oil may be achieved by?

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A Boiling the oil with water
B Boiling the oil with a catalyst
C Treating the oil with sodium hydroxide
D Treating the oil with hydrogen and catalyst
E Distilling oil under reduced pressure

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Question 28:

Hardening of an oil may achieved by?

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A Boiling the oil with water
B Boiling the oil with a catalyst
C Treating the oil with sodium hydroxide
D Treating the oil with hydrogen and catalyst
E Distilling oil under reduced pressure

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Question 29:

A cold aqueous solution of sodium chloride is electrolyzed using a graphite anode and an iron cathode. In the course of the electrolysis the electrolyte is continuously stirred. The liquid left after electrolysis will therefore consist of?

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A Sodium hydroxide solution
B Chlorine water
C Pure water
D Sodium hypochlorite solution
E Hydrochloric acid solution

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Question 30:

The best way of collecting chlorine is?

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A By downward displacement of air
B By upward displacement of air
C Over water
D Under water
E Over mercury

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