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.

2,741.

In the preparation of carbon monoxide by heating ethanedioic acid with concentrated sulphuric acid, the concentrated sulphuric acid act as?

A.

an oxidizing agent

B.

a reducing agent

C.

a dehydrating agent

D.

a reaction medium

E.

a catalyst

Correct answer is C

No explanation has been provided for this answer.

2,743.

Which of the following is a neutralization reaction? Addition of

A.

nitric acid to hydrochloric acid

B.

nitric acid to sulphuric acid

C.

nitric acid to distilled water

D.

nitric acid to sodium hydroxide

E.

sodium chloride to distilled water

Correct answer is D

No explanation has been provided for this answer.

2,744.

An element X has two isotopes, \(^{20} _{10}X\) and \(^{22} _{10}X\),
present in the ratio 1:3. The relative atomic mass of X would be?

A.

20.5

B.

21.0

C.

21.5

D.

22.0

E.

22.5

Correct answer is C

The relative atomic mass will be [(20 * 1) + (3 * 22)] / (4)
(86)/(4) = (43)/(2) = 21.5

2,745.

When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will?

A.

decrease, since only a fraction of the water molecules has changed to vapour

B.

remain constant, because the total number of water molecules has not changed

C.

increase, because the water molecules can now reach every part of the sealed tube

D.

decrease, since water boils under reduced pressure

E.

increase, because the water vapour molecules now strike the walls of the tube more frequently because of their increased velocity

Correct answer is E

No explanation has been provided for this answer.