Electrolysis - Jamb Chemistry Past Questions and Answers

Question 16:

• JAMB 1983

Which of the following happens during the electrolysis of molten sodium chloride?

A. Sodium ion loses an electron
B. Chlorine atom gains an electron
C. Chlorine ion gains an electron
D. Sodium ion is oxidized
E. Chloride ion is oxidized

Question 17:

• JAMB 1984

Sulphur

A. Forms two alkaline oxides
B. Is spontaneously flammable
C. Burns with a blue flame
D. Conducts electricity in the molten state
E. Is usually stored in the form of sicks in water

Question 18:

• JAMB 1984

If the cost of electricity required to deposit 1 g of magnesium is N5.00, how much would it cost to deposit 10g of aluminium?

A. N 10.00
B. N27.00
C. N44.44
D. N66.67
E. N33.33

Question 19:

• JAMB 1984

Which of the following electrodes is used in electrolysis of bauxite (Al₂O₃) in molten cryolite?

A. Steel electrodes
B. Carbon electrodes
C. Mercury electrodes
D. Carbon anode and steel cathode
E. Carbon cathode and stell anode

Question 20:

• JAMB 1985

A correct electrochemical series can be obtained from K, Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging?

A. Al and Mg
B. Zn and Fe
C. Zn and Pb
D. Pb and H
E. Au and Hg