WAEC Past Questions and Answers - Page 1514

7,566.

Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]

A.

NH3 = 17

B.

NH4CI = 53.5

C.

NH4NO3 = 80

D.

(NH3)2SO4 = 132

Correct answer is A

No explanation has been provided for this answer.

7,567.

What is the mass of 6.02 x 1024 atoms of magnesium? [Mg = 24, Avogadro constant = 6.02 x 1023 atoms mol-1]

A.

240g

B.

24g

C.

2.4g

D.

0.24g

Correct answer is A

No explanation has been provided for this answer.

7,568.

Bees are regarded as the friends of the farmer because they

A.

Usually sting the farmer

B.

Are harmless insects

C.

Help in pollination

D.

Produce nectar for human use

Correct answer is C

No explanation has been provided for this answer.

7,569.

The force of attraction between covalent molecules is?

A.

electrostatic attraction

B.

hydrogen bonding

C.

ionic force

D.

van der Waals forces

Correct answer is A

Covalent bond involves the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons.

7,570.

Water molecules are held together by

A.

covalent bond

B.

hydrogen bond

C.

ionic forces

D.

van der Waals forces

Correct answer is B

No explanation has been provided for this answer.