WAEC Past Questions and Answers - Page 1785

8,921.

Which of the following involves the decomposition enzymic action?

A.

Esterification

B.

Fermentation

C.

Dehydration

D.

Polymerization

E.

Saponification

Correct answer is B

No explanation has been provided for this answer.

8,922.

Why would an extension officer prefer the use of television to radio when introducing a new technology to farmers?

A.

The extension officer can get immediate feedback

B.

The farmer can observe the various steps involved

C.

Radio programmes are not reliable and clear enough

D.

It is cheaper to use television than radio

Correct answer is B

No explanation has been provided for this answer.

8,923.

Consider the compounds represented by the following general formula: X2SO4 Y2(SO4)3, 24H2OX and Y could respectively be

A.

K and AI

B.

Fe and K

C.

AI and Fe

D.

AI and K

E.

Cr and K

Correct answer is A

No explanation has been provided for this answer.

8,924.

When iron rusts, it undergoes

A.

deliquescence

B.

chemical decomposition

C.

hydrolysis

D.

redox reaction

E.

combustion

Correct answer is D

No explanation has been provided for this answer.

8,925.

What is the change in the oxidation number of phosphorus in the the reaction represented by the following equation? 4P (s) + 5O(2)(g) → 2P2O5(g)

A.

0 to + 2

B.

0 to 5

C.

+4 to + 2

D.

+4 to +5

E.

+4 to +7

Correct answer is B

No explanation has been provided for this answer.