JAMB Chemistry Past Questions & Answers - Page 332

1,656.

The compound that is used as an anesthetic is?

A.

CCl4

B.

CH Cl3

C.

CH2Cl2

D.

CH3Cl

Correct answer is B

- Chloroform / tricholoromethane ( CHCl\(_3\) ) is a potent anaesthetic agent.

- Though Chloroform is no longer used as an anaesthetic for several reasons, the most important of which is the relatively high risk of complications, including possible heart failure

1,657.

Two hydrocarbons X and Y were treated with bromine water. X decolorised the solution and Y did not not. Which class of compound does Y belong?

A.

Benzene

B.

Alkynes

C.

Alkenes

D.

Alkanes

Correct answer is D

Bromine water is an orange solution of bromine. It becomes colorless when it is shaken with an alkene. Alkenes can decolorize bromine water, but alkanes cannot.

X is ethene which decolorizes bromine water showing that ethene is unsaturated.

Y is an alkane. 

1,658.

The haloalkanes used in dry-cleaning industries are?

A.

trichloromethane and tetrachloromethane

B.

chloroethene and dichloroethene

C.

trichloroethene and tetrachloroethene

D.

chloroethane and dichloroethene

Correct answer is A

- Both  trichloromethane and tetrachloromethane are such important organic solvent.

1,659.

One of the major uses of alkane is?

A.

as domestic and industrial fuel

B.

in the hydrogenation of oils

C.

in the textile industries

D.

in the production of plastics

Correct answer is A

- Alkanes will react with Oxygen if they are given sufficient Activation Energy. This will result in a highly Exothermic reaction, producing Carbon Dioxide and Water, which makes Alkanes very useful as fuels.

1,660.

The correct order of increasing boiling points of the following compounds C3H7OH, C7H16 and C4H10 is?

A.

C3H7OH → C4H10 → C7H10

B.

C4H10 → C7H16 → C3H7OH

C.

C7H16 → C3H7OH → C4H10

D.

C4H10 → C3H7OH → C7H16

Correct answer is D

C3H7OH ( PROPANOL) ⇒ 97ºC

 C7H16 ( HEPTANE ) ⇒ 98.42ºC ;and

C4H10 ( BUTANE ) ⇒ -1ºC