WAEC Past Questions and Answers - Page 1618

8,086.

What is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

A.

Oxygen

B.

Hydrogen

C.

Nitrogen

D.

Copper

Correct answer is D

No explanation has been provided for this answer.

8,087.

What is the oxidation number of nitrogen in AI(NO3)3?

A.

+ 1

B.

+ 3

C.

+ 5

D.

+ 6

Correct answer is C

No explanation has been provided for this answer.

8,088.

A reaction is represented by the equation below. A2(g) + B2(g) 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct?

A.

The reaction goes to completion at equilibrium

B.

The forward reaction is exthermic

C.

At equilibrium increase in temperature favours the reverse reaction

D.

Pressure has no effect on the equilibrium mixture

Correct answer is D

No explanation has been provided for this answer.

8,089.

Consider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = _65.7 kJmol-1. From the equation, it can be deduced that

A.

direct combination is involved and the reaction is endothermic

B.

a solid is formed and heat is evolved

C.

activation energy is high and a catalyst is required

D.

the reaction is endothermic and occurs at high temperature

Correct answer is B

No explanation has been provided for this answer.

8,090.

What does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = - 363 kJ mol-1

A.

lonization energy

B.

Electron affinity

C.

Dissociation energy

D.

Heat of atomization

Correct answer is B

No explanation has been provided for this answer.