NECO Chemistry Past Questions & Answers - Page 21

101.

Ethene decolourises acidified potassium tetraoxomanganate(VII) solution. Which gas will decolourise bromine water?

A.

CH4

B.

C2H6

C.

C3H6

D.

C3H8

E.

C6H6

Correct answer is C

No explanation has been provided for this answer.

102.

Which method is used for the purification of copper from its ore?

A.

distillation

B.

electrochemical

C.

electrolysis

D.

neutralization

E.

reduction

Correct answer is C

No explanation has been provided for this answer.

103.

What is the concentration (in mol dm3) of a solution containing 28 g of potassium hydroxide per 100 cm3 of solution? (K=39; H=1; 0=16)

A.

0.01

B.

0.05

C.

0.1

D.

0.5

E.

2.8

Correct answer is B

No explanation has been provided for this answer.

104.

At s.t.p, a mole of chlorine occupies 22.4dm3. If the temperature is changed to 35°C and the pressure to 750mHg the of the new volume will be [Cl = 35.5]

A.

\( ^{\text{760 x 22.4 x 308}} \text{750 x 273x 35.5} dm^3 \)

B.

\( ^{\text{760 x 22.4 x 308}} \text{750 x 273}^x dm^3 \)

C.

\( ^{\text{750 x 22.4 x 35.5}} \text{760 x 273dm3} \)

D.

\( ^{\text{760 x 22.4 x 35.5}} \text{750x22.3x273} \)

E.

\( ^{\text{760 x 22.4 x 35.5}} \text{750 x 308dm3} \)

Correct answer is B

No explanation has been provided for this answer.

105.

How many Faradays of electricity are required to liberate 9g of aluminium? [Al = 27]

A.

0.1

B.

0.3

C.

1

D.

2.7

E.

3

Correct answer is C

No explanation has been provided for this answer.