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.

1,231.

If the relative molecular mass of an element is not a whole number, it can be deduced that the element is

A.

naturally radioactive

B.

abundant in nature

C.

a transition metal

D.

an isotopic mixture

Correct answer is D

No explanation has been provided for this answer.

1,232.

The oxide from electric power station is

A.

carbon (IV) oxide

B.

copper (ll) oxide

C.

nitrogen (IV) oxide

D.

sulphur (IV) oxide

Correct answer is C

 Nitric oxide is an important component of the air pollution generated by automotive engines and thermal power-generating plants.

sulphur dioxide may also be produced in case of fuel containing sulphur, Nigeria crude is sulphur free,

1,233.

The most common process in the extraction of metals from their ore is

A.

catalysis

B.

electrolysis

C.

oxidation

D.

reduction

Correct answer is D

No explanation has been provided for this answer.

1,234.

Which of the following gases is used to retard the vaporization of the filament in a light bulb?

A.

Argon

B.

Helium

C.

Hydrogen

D.

Oxygen

Correct answer is A

No explanation has been provided for this answer.

1,235.

The purity of a solid sample can best be determined by its?

A.

boiling point

B.

melting point

C.

conductivity

D.

solubility

Correct answer is B

- The presence of impurities in a substance results in a lower melting point due to a process called melting point depression.

- That implies a pure solid has a SHARP melting point which is of the standard value when compared.