Waec Chemistry 2021 Past Questions and Answers

Question 21:

• WAEC 2021

The ratio of carbon atoms of hydrogen atoms in a hydrocarbon is 1:2. If its molecular mass is 56, what is its molecular formula?

A. C\(_{3}\)H\(_{6}\)
B. C\(_{4}\)H\(_{8}\)
C. C\(_{2}\)H\(_{4}\)
D. CH\(_{2}\)

Question 22:

• WAEC 2021

What is the relative molecular mass of the compound below

[H = 1.0; C = 12.0; O = 16.0]

A. 137
B. 136
C. 64
D. 59

Question 23:

• WAEC 2021

Cathodic protection of metals is based on

A. Standard electrode potential of hydrogen
B. Its electrical conductivity
C. Nature of oxides formed
D. Relative tendencies of oxidation

Question 24:

• WAEC 2021

If humid air is polluted by chlorine discharged, the air can be restored by sprinkling

A. Solid MnO\(_{2}\)
B. Acidified KMnO\(_{4}\)
C. Acidified FeSO\(_{4}\)
D. Saturated NaCl(aq)

Question 25:

• WAEC 2021

The alkanol represented by the structure below is

A. Primary and dihydric
B. Secondary and monohydric
C. Tertiary and dihydric
D. Secondary and dihydric