JAMB Chemistry Past Questions & Answers - Page 251

1,251.

Which of the following can have an isomer?

A.

C2H4

B.

C4H10

C.

C3H8

D.

C2H6

E.

C6H6

Correct answer is B

Butane is an alkane with four carbon atoms so molecular formula is C4H10. It has two isomers; n-butane and isobutane.

1,252.

In the preparation of ammonia, which of the following is used as the drying agent?

A.

CaO

B.

CaCI2

C.

Conc. H2SO4

D.

P2O5

E.

H3PO4

Correct answer is A

No explanation has been provided for this answer.

1,253.

Which of the following processes takes place during electrolysis?

A.

Positive ions are discharged at the anode bby gaining sufficient electrons to become neutral

B.

Negative ions are dicharged at the anode by gaining suficient electrons to become neutral

C.

Positive ions are discharged at the anode by losing sufficient electrons to become neutral

D.

Negative ions are discharge at the anode by losing sufficient electrons to become neutral

E.

Nothing happens

Correct answer is D

During electrolysis, Negative ions are discharged at the anode by losing sufficient electrons to become neutral, and positive ions are discharged at the cathode by gaining sufficient electrons to become neutral.

1,254.

The brown coloration in nitric acid prepared in the laboratory can be removed by?

A.

heating the acid

B.

bubbling air through the acid

C.

cooling the acid

D.

adding a decolorizing agent

E.

adding a base

Correct answer is B

The color of nitrogen dioxide is reddish brown. This nitrogen dioxide when comes in contact with acid appears yellow in color.

This means the color of nitric acid can be removed by bubbling air through acid.

1,255.

In the reaction
C + 2HNO3 → CO2 + NO2 + NO + H2O nitric acid is acting as?

A.

a reducing agent

B.

a nitrating agent

C.

an oxidizing agent

D.

a catalytic agent

E.

a neutralizing agent

Correct answer is C

No explanation has been provided for this answer.