WAEC Past Questions and Answers - Page 1374

6,866.

Which of the following statements about intermolecular distances and cohesive forces between gas is correct? They are

A.

Both large

B.

Both negligible

C.

Constant and negligible

D.

Large and negligible

Correct answer is D

In a gas, the distance between molecules, whether monatomic or polyatomic, is very large compared with the size of the molecules; thus gases have a low density and are highly compressible.

Cohesive Force is negligible in case of gases.

6,867.

When a reaction is endothermic,

A.

Enthalpy change, \(\Delta\)H is negative

B.

Heat content of a product is less than the heat content of a reactant

C.

Heat content of reactants is less than the heat content of product

D.

The reaction is non-spontaneous

Correct answer is C

An endothermic reaction is any chemical reaction that absorbs heat from its environment. The absorbed energy provides the activation energy for the reaction to occur.

6,868.

Which of the following gases will diffuse most rapidly?

[H = 1.00, C = 12.0, O = 16.0, S = 32.0, Cl = 35.5]

A.

Cl2

B.

SO2

C.

CH4

D.

C2H6

Correct answer is C

No explanation has been provided for this answer.

6,869.

The vapour pressure of a liquid depends on:
I. Temperature II. rate of condensation III. Cohesive forces holding the particles together.

A.

I

B.

I and II

C.

I and III

D.

II and III

Correct answer is C

No explanation has been provided for this answer.

6,870.

The general gas equation was deprived from______?

A.

Boyle's and Gay Lussac's laws

B.

Boyle's and Graham's laws

C.

Boyle's and Charles' laws

D.

Dalton's atomic theory

Correct answer is C

No explanation has been provided for this answer.