JAMB Chemistry Past Questions & Answers - Page 222

1,106.

A mixture of starch solution and potassium iodide was placed in a test tube. On adding dilute tetraoxosulphate (lV) acid and then K2Cr2O7 solutions, a blue-black colour was produced. In this reaction, the?

A.

iodide is oxidized

B.

tetraoxosulphate (Vl) acid acts as an oxidizing agent

C.

starch has been oxidized

D.

K2Cr2O7 is oxidized

Correct answer is C

No explanation has been provided for this answer.

1,107.

Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution?

A.

Cu2+ + 2e- → Cu(s)

B.

2Cl- -2e → Cl2

C.

Cu(s) -2e → Cu2+(aq)

D.

Cu2+(aq) + 2Cl-(aq) → CuCl2(aq)

Correct answer is A

No explanation has been provided for this answer.

1,108.

Which of the following acts both s a reducing and an oxidizing agent?

A.

H2

B.

SO2

C.

H2S

D.

C

Correct answer is B

SO2 = i.e
In H2SO2 act as oxidizing agent
H2S + SO2 → 3S + 2H2O
Whereas in water SO2 acts as reducing agents H2O + SO2 H2SO23

1,109.

Which of the following substances is a basic salt?

A.

Na2CO3

B.

Mg(OH)CI

C.

NaHCO3

D.

KSO4.AI2(SO4)3,24H2O

Correct answer is B

No explanation has been provided for this answer.

1,110.

What volume of a 0.1 M H3PO4 will be required to neutralize 45.0 cm3 of a 0.2 M NaOH?

A.

10.0 cm3

B.

20.0 cm3

C.

27.0 cm3

D.

30.0 cm3

Correct answer is D

No explanation has been provided for this answer.