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.

3,516.

What volume of 0.5 mol dm-3 H2SO4 will exactly neutralize 20cm3 of 0.1 mol dm-3 NaOH solution?

A.

2.0 cm3

B.

5.0 cm3

C.

6.8 cm3

D.

8.3 cm3

Correct answer is A

2NaOH + H2SO4 → Na2SO4 + 2H2O
CaVa/CbVb = ratio of acid/ratio of base
(0.5 * Va)/(0.1 * 20) = 1/2
∴ Va = 2.0cm

3,517.

Which of the following compound is a normal salt?

A.

NaHS

B.

NaHSO4

C.

NaHCO3

D.

Na2CO3

Correct answer is D

No explanation has been provided for this answer.

3,518.

Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a

A.

solution

B.

suspension

C.

precipitate

D.

colloid

Correct answer is C

No explanation has been provided for this answer.

3,519.

The solubility in mol dm/-3 of 20g of CuSO4 dissolved in 100g of water at 180o is
[Cu = 64, S = 32, O =16]

A.

0.13

B.

0.25

C.

1.25

D.

2.00

Correct answer is C

Relative molecular mass of CuSO4 = 64 + 32 + 16 * 4 = 160
The number of moles of CUSO4 = reacting mass/molecular mass = 20/160 = 0.125
100g of water dissolved 0.125m of CuSO4
100g of water will dissolve (0.125 * 1000)/100 = 1.25mol dm3

3,520.

A carcinogenic substance is

A.

asbestos dust

B.

sawdust

C.

nitrogen (II) oxide

D.

carbon (II) oxide

Correct answer is A

No explanation has been provided for this answer.