WAEC Chemistry Past Questions & Answers - Page 128

636.

The bonds in crystalline ammonium chloride are

A.

covalent and dative

B.

ionic and covalent

C.

ionic, covalent and dative

D.

ionic, covalent and hydrogen bond

Correct answer is C

N makes three covalent bonds with three Hydrogen and a coordinate (dative covalent) bond with with hydrogen ion, forming ammonium ion (NH\(_4 ^+\). The ammonium ion forms an ionic bond with chloride ion to form NH\(_4\)Cl.

637.

In metallic solid, the forces of attraction is between the mobile valence electrons and the

A.

atoms

B.

neutrons

C.

negative ions

D.

positively charged nuclei

Correct answer is D

No explanation has been provided for this answer.

638.

Which of the following bond types is responsible for the high boiling point of water?

A.

Metallic bond

B.

Covalent bond

C.

lonic bond

D.

Hydrogen bond

Correct answer is D

The high boiling point is due to the breaking of the intermolecular force called Hydrogen bond.

639.

In which of the following series are the atoms arranged in order of increasing ionization energy?

A.

Li, Na K

B.

B, Be, Li

C.

O, F, Ne

D.

Be, mG, Ca

Correct answer is C

The ionization energy increases across the period. It increases up the group.

640.

In the periodic table, alkaline earth metals can be found in group

A.

l

B.

ll

C.

VI

D.

VII

Correct answer is B

No explanation has been provided for this answer.