JAMB Past Questions and Answers - Page 1579

7,891.

A substance S is isomorphous with another substance R. When a tiny crystals of S is added into a supersaturated solution of R?

A.

S dissolves in the solution

B.

crystals of R are precipitated

C.

there is no observable change

D.

R and S react to generate heat

Correct answer is B

No explanation has been provided for this answer.

7,892.

The ion that may be assumed to have negligible concentration in a sample of water that lathers readily with soap is?

A.

Mg+

B.

K+

C.

CO22-

D.

HCO3

Correct answer is A

Calcium and magnesium ions (particularly calcium) negatively influence cleansing power of detergents, because these form nearly insoluble salts with soap. When the water lathers readily, it means these ions are in negligible concentration in the water.

7,893.

Starch can be converted to ethyl alcohol by?

A.

distillation

B.

fermentation

C.

isomerization

D.

cracking

Correct answer is B

No explanation has been provided for this answer.

7,894.

Which of the following are made by the process of polymerization?

A.

Nylon and soap

B.

Nylon and artificial rubber

C.

Soap and butane

D.

Margarine and nylon

Correct answer is B

No explanation has been provided for this answer.

7,895.

The general formula of an alkyl halide (where X represents the halide) is?

A.

CnH2n 2X

B.

CnH2n + 1X

C.

CnH2n + 2X

D.

CnH2nX

Correct answer is B

No explanation has been provided for this answer.