Electrolysis - Jamb Chemistry Past Questions and Answers

Question 26:

• JAMB 1988

Crude copper can be purified by the electrolysis of CuSO_4(aq) if?

A. Platinum electrodes are used
B. The crude copper is made the anode of the cell
C. The crude copper is made the cathode of the cell
D. Crude copper electrodes are used

Question 27:

• JAMB 1988

Use the graph above to answer this question. The mass of a substance, M, liberated at an electrode during electrolysis is proportional to the quantity of electricity, Q passing through the electrolyte. This is represented graphically by.

A. A
B. B
C. C
D. D

Question 28:

• JAMB 1989

The same current is passed for the same time through solutions of AgNO₃ and CuSO₄ connected in series. How much silver will be deposited if 1.0 g of copper is produced?
[Cu = 63.5, S = 32, O = 16, Ag = 108, N = 14]

A. 1.7 g
B. 3.4 g
C. 6. 8 g
D. 13. 6 g

Question 29:

• JAMB 1989

What is discharged at the cathode during the electrolysis of copper (ll) tetraoxosulphate (VI) solution?

A. Cu ²⁺ only
B. H [sup][/sup]+ only
C. Cu ²⁺ and H
D. Cu ²⁺ and SO ^2-

Question 30:

• JAMB 1989

The scale of a chemical balance is made of iron plate and coated with copper electrolytically because

A. Iron is less susceptible to corrosion than copper
B. Copper is twice as less susceptitible to corrosion as iron
C. Copper is less susceptible to corrosion than iron
D. Copper and iron are equally susceptible to corrosion