Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

1,061.

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.

1,062.

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.

1,063.

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.

1,064.

Which metal bromide is widely used in photography?

A.

calcium bromide

B.

magnesium bromide

C.

potassium bromide

D.

silver bromide

E.

sodium bromide

Correct answer is D

No explanation has been provided for this answer.

1,065.

What change will occur during the electrolysis of brine using carbon electrodes?

A.

Chlorine will be given off at the anode

B.

Oxygen gas will be given off at the anode

C.

Sodium will be deposited at the cathode

D.

The resulting solution, after electrolysis, will be acidic.

E.

The volumes of hydrogen and chlorine given off during the same time are equal

Correct answer is A

Chlorine is discharged as follows:

\(Cl^- \to Cl + e^-\)

\(Cl + Cl \to Cl_{2(g)}\)

This reaction occurs at the anode.