WAEC Chemistry Past Questions & Answers - Page 26

126.

Under which conditions of pressure (p) and temperature (T) would the volume of an inflated ballon increase? When

A.

P and T are increased

B.

both T and P are decreased

C.

T is increased and P is decreased

D.

T is decreased and P is increased

Correct answer is C

No explanation has been provided for this answer.

127.

Consider the structure above

How many carbon atoms does the parent chain contain? 

A.

5

B.

4

C.

3

D.

2

Correct answer is B

Going by the longest continuous carbon chain, the parent chain contains 4 carbon atoms (2- methyl butanoic acid)

128.

When CuSO\(_{4(aq)}\) is added to Pb(NO\(_{3}\))\(_{2(aq)}\)--------

A.

there would be no visible change

B.

a blue precipitate would be formed

C.

the resulting solution would become colourless

D.

a white precipitate would be formed

Correct answer is D

No explanation has been provided for this answer.

129.

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.

130.

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