WAEC Chemistry Past Questions & Answers - Page 119

591.

The vapour pressure of a liquid depends on l. temperature. ll. rate of condensation. III. cohesive forces holding the particles together

A.

l only

B.

l and ll only

C.

l and lll only

D.

ll and lll only

Correct answer is C

Three common factors that influence the vapor pressure of a liquid are the surface area, intermolecular forces and the temperature.

592.

The complex compound formed when aluminum dissolves in aqueous sodium hydroxide is

A.

Na3Al(OH)4.

B.

NaAl(OH)4

C.

NaAl(OH)3

D.

Na2Al(OH)3

Correct answer is B

When aluminium is treated with dilute sodium hydroxide it forms a salt called sodium tetrahydroxoaluminate and hydrogen gas.

593.

The complex compound formed by the combination of two elements with a large electronegativity difference is likely to be

A.

polar covalent

B.

giant molecular

C.

covalent

D.

ionic

Correct answer is D

Ionic bonds are also formed when there is a large electronegativity difference between two atoms.

594.

The shape of a graphite crystal is

A.

tetrahedral

B.

pyramidal

C.

hexagonal

D.

octahedral

Correct answer is C

Graphite is a crystalline form of the element Carbon. The atoms are arranged in a hexagonal structure.

595.

Which of the following halogens is liquid at room temperature?

A.

Chlorine

B.

Fluorine

C.

lodine

D.

Bromine

Correct answer is D

Bromine is the third lightest halogen. It is a fuming red-brown liquid at room temperature.