Electrolysis - Jamb Chemistry Past Questions and Answers

Question 51:

• JAMB 1998

The soil around a battery manufacturing factory is likely to contain a high concentration of?

A. Ca²⁺ salts
B. Pb²⁺ salts
C. Mg²⁺ salts
D. Al³⁺ salts

Question 52:

• JAMB 1998

Mg²⁺_(aq) + 2e^->_(aq) → Mg_(s)E°_(volts) = 2.370
Zn²⁺_(aq) + 2e^->_(aq) → Zn_(s)E°_(volts) = -0.763
Cds²⁺_(aq) + 2e^->_(aq) → Cd_(s)E°_(volts) = 0.403
Cu²⁺_(aq) + 2e^->_(aq) → Cu_(s)E°_(volts) = 0.340
In the electrochemical series above, the strongest reducing agents is?

A. Cu _(s)
B. Cd_(s)
C. Znsub>(s)
D. Mg_(s)

Question 53:

• JAMB 1999

200cm³ each of 0.1M solutions of lead (II) trioxonitrate (V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated.
[Pb = 207, Cl= 35.5, N = 14, O = 16]

A. 2.78g
B. 5.56g
C. 8.34g
D. 11.12g

Question 54:

• JAMB 1999

What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?
[ F = 96 5000 C mol^-1 ]

A. 24 125 coulombs
B. 48 250 coulombs
C. 72 375 coulombs
D. 96 500 coulombs

Question 55:

• JAMB 1999

When a current I was passed through an electrolyte solution for 40 minutes, a mass X g of a univalent metal was deposited at the cathode. What mass of the metal will be deposited when a current 2I is passed through the solution for 10 minutes?

A. X/4 g
B. X/2 g
C. 2X g
D. 4X g