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.

1,156.

What volume of 0.5mldm3 H2SO4 will exactly neutralize 20cm3 of 0.1moldm3 NaOH Solution?

A.

2.0cm3

B.

5.0cm3

C.

6.8cm3

D.

8.3cm3

Correct answer is A

2NaOH + H2SO4 → Na2SO4 + 2H2O
CaVa) ÷ (CbVb) = ratio of acid / ratio of base
0.5Va ÷ (0.1 × 20) = ½
Va = 2.0cm3

1,157.

The energy value of petrol can be determined by

A.

Bomb calorimeter

B.

Catalytic cracker

C.

Fractionating column

D.

Thermometer

Correct answer is C

Fractionating column contains petrol with different densities.

1,158.

The basic particles from which matter could be made up of are as follow, except?

A.

Salt

B.

Atom

C.

Ion

D.

Molecule

Correct answer is A

Salt is a chemical used for varieties of purposes, so it’s not part of matter, Atom being the smallest part of molecule and ion are charge which are part of matter

1,159.

The number of isomers formed by C6H14 is

A.

4

B.

5

C.

2

D.

3

Correct answer is B

The number of isomers C6H14 cm is 5. it will not form options A,C, D

1,160.

\(Cu_2S_{(s)}+ O_{2(g)} = 2CU_{(s)} + SO_{2(g)}\).

In the above reaction, the oxidation number of Cu changes from ___ to _______?

A.

+1 to 0

B.

0 to +2

C.

+2 to +1

D.

0 to +1

Correct answer is A

The oxidation number is from +1 to O as a result of the release of sulphur. Options B, C, and D are not the actual oxidation number for copper