WAEC Chemistry Past Questions & Answers - Page 150

746.

Chemicals that are produced in small quantities and with very high degree of purity are

A.

bulk chemicals

B.

fine chemicals

C.

heavy chemicals

D.

light chemicals

Correct answer is B

No explanation has been provided for this answer.

747.

Which of the following substances causes the depletion of the ozone layer in the atmosphere?

A.

Carbon (IV) oxide

B.

Chlorofluorocarbon

C.

Sulphur (IV) oxide

D.

Hydrocarbons

Correct answer is B

No explanation has been provided for this answer.

749.

A hydrocarbon containing 88.9% carbon has the empirical formula [H = 1 C = 12]

A.

CH

B.

CH2

C.

C2H3

D.

C2H5

Correct answer is B

No explanation has been provided for this answer.

750.

Arrange the following compounds in order of increasing boiling point
l.CH 3CH2CH2OH
II.CH 3CH 2OH
III.CH3CH2CH2CH2OH
IV. CH3CH 2CH2CH 2CH 3

A.

I < II < IV < III

B.

IV < III < II < I

C.

I < II < III < IV

D.

IV < I < II< III

Correct answer is D

Ethanol 78°C
Propanol 97°C
Butanol 118°C
Pentane 36.1°C

Hence, the arrangement is IV, I, II, III.