JAMB Chemistry Past Questions & Answers - Page 411

2,051.

C(s) + 2S(g) → CS2(g)
ΔH = +89 kJ mol-1
The chemical equation above implies that

A.

each of carbon and sulphur has 89 kJ of energy

B.

both carbon and sulphur contribute 89 kJ of energy

C.

89 kJ of energy is released

D.

89 kJ of energy is absorbed

Correct answer is D

No explanation has been provided for this answer.

2,052.

Ethanoic acid is

A.

tribasic

B.

unionizeable

C.

monobasic

D.

dibasic

Correct answer is C

No explanation has been provided for this answer.

2,053.

What current in amperes will deposit 2.7g of aluminium in 2 hours?
[Al = 27, F = 96 500 C mol-1]

A.

32

B.

8

C.

4

D.

16

Correct answer is C

Al3+ + 3e → Al
3 * 96500 → 27
I = 3600 * 2 → 27
I = (2.7/27) * ((3 * 96500)/(3600 * 2))
= 4.025 ≈ 4

2,054.

Which of the following best explains the increase in the rate of a chemical reaction as the temperature rises?

A.

The bonds in the reacting molecules are more readily broken

B.

The molecular collisions become more violent

C.

A lower proportion of the molecules has the necessary minimum energy to react

D.

The collision frequency of the molecules increase

Correct answer is D

No explanation has been provided for this answer.

2,055.

A metal M displaces zinc from zinc chloride solution. This shows that

A.

M is more electronegative than zinc

B.

Zinc is above hydrogen in the series

C.

M is more electropositive than zinc

D.

Electrons flow from zinc to M

Correct answer is C

No explanation has been provided for this answer.