JAMB Chemistry Past Questions & Answers - Page 249

1,241.

Which of the following types of reactions takes place between C2H6 and the halogens?

A.

Substitution

B.

Polymerization

C.

Addition

D.

Saponification

E.

Oxidation

Correct answer is A

Alkanes undergo a substitution reaction with halogens in the presence of light. For instance, in ultraviolet light , methane reacts with halogen molecules such as chlorine and bromine.

1,242.

Cotton is almost pure?

A.

starch

B.

protein

C.

animal fibre

D.

celluose

E.

mineral fibre

Correct answer is D

No explanation has been provided for this answer.

1,243.

Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is?

A.

calcium

B.

calcium oxide

C.

calcium carbide

D.

sodium peroxide

E.

sodium sulphate

Correct answer is C

No explanation has been provided for this answer.

1,244.

An amphoteric oxide is an?

A.

amorphous oxide of a metal

B.

amorphous oxide of a non-mental

C.

oxide that is insoluble in water

D.

oxide that behaves both as a base as well as an acid

E.

oxide that loses its oxygen on sublimation

Correct answer is D

No explanation has been provided for this answer.

1,245.

Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes?

A.

Oxygen gas is given off at the cathode

B.

Hydrogen gas is given of at the anode

C.

Sodium metals is deposited at the anode

D.

Sodium metal is deposited at the cathode

E.

Alkalinity at the cathode increases

Correct answer is E

No explanation has been provided for this answer.