JAMB Chemistry Past Questions & Answers - Page 165

821.

Vulcanization of rubber is a process by which

A.

isoprene units are joined to produce rubber

B.

rubber latex is coagulated

C.

sulphur is chemically combined in the rubber

D.

water is removed from the rubber

Correct answer is C

No explanation has been provided for this answer.

822.

When excess chlorine is mixed with ethene at room temperature, the product is

A.

1,2 - dichloroethane

B.

1,2 - dichloroethene

C.

1,1 - dichloroethane

D.

1, 1 - dichloroethene

Correct answer is A

No explanation has been provided for this answer.

823.

Which of the following is NOT involved in the extraction of metals from their ores?

A.

reduction with carbon

B.

reduction with other metals

C.

reduction by electrolysis

D.

oxidation with oxidizing agents

Correct answer is D

No explanation has been provided for this answer.

824.

Mortar is NOT used for under-water construction because

A.

it hardens by lose of water

B.

its hardening doe not depend upon evaporation

C.

it requires concrete to harden

D.

it will be washed away by the flow of water

Correct answer is A

No explanation has been provided for this answer.