WAEC Past Questions and Answers - Page 1743

8,711.

Which of the following structures is not a part of the digestive tract of pigs?

A.

Oesophagus

B.

Proventriculus

C.

Duodenum

D.

Colon

Correct answer is B

No explanation has been provided for this answer.

8,712.

Chlorine is prepared on a large scale by the

A.

electrolysis of concentrated sodium chloride solution

B.

action of manganese (IV) oxide on hot concentrated hydrochloric acid

C.

action of concentrated tetraoxosulphate (IV) acid on sodium chloride

D.

oxidation of concentrated hydrochloric acid with potassium tetraxosulphate (VII)

E.

action of dilute mineral acids on bleaching powder

Correct answer is A

No explanation has been provided for this answer.

8,713.

Hybrid vigour in crop improvement is brought about through

A.

Introduction

B.

Mass selection

C.

Inbreeding

D.

Cross breeding

Correct answer is D

No explanation has been provided for this answer.

8,714.

Which of the following oxides is amphoteric?

A.

Na2O

B.

Fe2O3

C.

AI2O3

D.

CaO

E.

CuO

Correct answer is C

No explanation has been provided for this answer.

8,715.

The use of fungal pathogens to control dodder weed is a

A.

Physical method

B.

Mechanical method

C.

Biological method

D.

Cultural method

Correct answer is C

No explanation has been provided for this answer.