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.

246.

What would be observed when aqueous ammonia is added in drops and then in excess to a solution of copper(II) ions?

A.

blue precipitate is formed which is soluble in excess ammonia

B.

brick red precipitate is produced which is insoluble in excess ammonia

C.

which precipitate is formed which is excess in ammonia

D.

green precipitate is formed which is insoluble in excess ammonia

Correct answer is A

No explanation has been provided for this answer.

247.

The basic property of salts used as drying agents is by?

A.

efforescence

B.

high melting point

C.

hygroscopy

D.

low solubility

Correct answer is C

 Hygroscopic substances are used to keep products dry or to remove water from an area. They are commonly used in desiccators
Some common examples of hygroscopic substances include: Sodium chloride. Zinc chloride. Calcium chloride

249.

The most common method of preparing insoluble salts is by

A.

filtration

B.

decomposition

C.

neutralization

D.

double decomposition

Correct answer is D

No explanation has been provided for this answer.

250.

A molecular of phosphorus is

A.

diatomic

B.

triatomic

C.

tetraatomic

D.

monoatomic

Correct answer is C

No explanation has been provided for this answer.