WAEC Chemistry Past Questions & Answers - Page 184

916.

HNO3 does not usually react with metals to liberate hydrogen because HNO3 is

A.

a strong acid

B.

a corrosive acid

C.

an oxidizing agent

D.

a nitrating agent

Correct answer is C

This is because nitric acid is a strong oxidizing agent. When it reacts with metals it tends to oxidize the metal but the hydrogen in it does not get reduced to hydrogen gas.

917.

Which of the following statements is not a postulate of the kinetic theory of gases?

A.

Molecules move with the same speed

B.

intermolecular forces are negligible

C.

Molecules are in a state of constant random motion

D.

collision between molecules is elastic

Correct answer is A

No explanation has been provided for this answer.

918.

When X is heated with manganese (IV) oxide, oxygen is produced X is

A.

KCI

B.

KCIO3

C.

CaCO3

D.

ZnCO3

Correct answer is B

No explanation has been provided for this answer.

919.

Which of the following factors does not affect the rate of reaction of CaCO3 with HCI?

A.

temperature of the reaction

B.

solubility of the CaCO3

C.

concentration of the HCI

D.

surface area of the CaCO3

Correct answer is B

No explanation has been provided for this answer.

920.

The activation energy of a reaction can be altered by

A.

adding a reducing agent

B.

applying a high pressure

C.

using a catalyst

D.

changing the temperature

Correct answer is C

No explanation has been provided for this answer.