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Friday, 08 May 2026
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Chemistry Past Questions and Answers

Topic: Electrolysis

Jamb Chemistry Questions - Electrolysis

Question 1:
During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
  • A The litmus turns blue but no gas is evolved
  • B The litmus turns blue and oxygen is evolved
  • C The litmus turns blue and hydrogen is evolved
  • D The litmus turns red and oxygen is evolved
  • E The litmus turns red and then becomes colourless
View Answer & Explanation
Question 2:
During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
  • A The litmus turns blue but no gas is evolved
  • B The litmus turns blue and oxygen is evolved
  • C The litmus turns blue and hydrogen is evolved
  • D The litmus turns red and oxygen is evolved
  • E The litmus turns red and then becomes colourless
View Answer & Explanation
Question 3:
In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode
  • A Sulphur hydrogen
  • B Hydrogen oxygen
  • C Oxygen Hydrogen
  • D Hydrogen sulphate ions
  • E Sulphur oxygen
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Question 4:
0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64]
  • A 64.0g
  • B 32.0g
  • C 16.0g
  • D 6.4 g
  • E 3.2g
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Question 5:
In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because
  • A It makes bauxite a better conductor of electricity
  • B It makes bauxite melt at a lower temperature
  • C It makes aluminium purer
  • D It prevents aluminium from getting oxidized
  • E It protects the carbon electrodes used in the process
View Answer & Explanation