JAMB Chemistry Past Questions & Answers - Page 429

2,141.

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

Correct answer is B

4 Faradays of electricity is required to liberate one mole of oxygen gas
∴ quantity of electricity required
= 0.125 * 4 * 96500 = 48250 coulombs

2,142.

N2O4(g) ↔ 2NO2(g). Increase in total pressure of the equilibrium reaction above will

A.

produce more of NO2(g) in the mixture

B.

convert all of N2O4(g) to NO2(g)

C.

have no effect on the concentrations of NO2(g)and N2O4(g)

D.

produce more of N2O4(g) in the mixture

Correct answer is D

No explanation has been provided for this answer.

2,143.

2SO2(g) + O2(g) ↔ 2SO3(g). In the chemical reaction above, the substance that will increase the rate of production of sulphur (VI) oxide is

A.

manganese (IV) oxide

B.

finely divided iron

C.

vanadium (V) oxide

D.

nickel

Correct answer is C

No explanation has been provided for this answer.

2,144.

The entropy and enthalpy of a system are a measure of

A.

degree of disorderlinesss and heat content respectively

B.

heat content and degree of disorderliness respectively

C.

heat content of a system only

D.

degree of disorderliness only

Correct answer is A

No explanation has been provided for this answer.

2,145.

The solubility product of Cu(IO3)2 is 1.08 * 10-7. Assuming that neither ions react appreciable with water to form H+ and OH-, what is the solubility of this salt?

A.

2.7 * 10-8 mol dm-3

B.

9.0 * 10-8 mol dm-3

C.

3.0 * 10-3 mol dm-3

D.

9.0 * 10-3 mol dm-3

Correct answer is D

No explanation has been provided for this answer.