WAEC Chemistry Past Questions & Answers - Page 160

796.

A mixture of kerosene and diesel oil can be separated by

A.

crystallization

B.

distillation

C.

precipitation

D.

sublimation

Correct answer is B

No explanation has been provided for this answer.

797.

Calculate the quantity of electricity passed when 0.4 A flows for 1 hour 20 minutes through an electrolytic cell

A.

4800C

B.

3840C

C.

1920C

D.

32C

Correct answer is C

No explanation has been provided for this answer.

798.

Oxidation takes place at the anode during electrolysis because the anode

A.

is deficient in electrons

B.

is deficient in protons

C.

has excess electrons

D.

has attraction for positive ions

Correct answer is C

No explanation has been provided for this answer.

799.

In dry Leclanche cell, manganese (IV) oxide acts as

A.

a reducing agent

B.

binding agent

C.

catalyst

D.

depolarizer

Correct answer is D

No explanation has been provided for this answer.

800.

Consider the equilibrium reaction represented by the equation: 2SO2(g) + O2(g) ⇌ 2SO3(g) ∆H = - 197 kJmol-1. At equilibrium, increase in the total pressure of the system brings about

A.

decrease in rate of the reaction of the system

B.

decrease in temperature of the system

C.

increase in temperature of SO3

D.

increase in concentration of SO2

Correct answer is C

No explanation has been provided for this answer.