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.

3,256.

The simplest branched-chain hydrocarbon is

A.

ethane

B.

ethene

C.

propane

D.

butane

Correct answer is D

The smallest branched alkane is isobutane. Notice that isobutane has the same molecular formula, C4H10, as n-butane but has a different structural formula.

3,257.

The molecular formula of a common organic laboratory anaesthetic is

A.

CHCl3

B.

CHI3

C.

CCl4

D.

CHF3

Correct answer is A

No explanation has been provided for this answer.

3,258.

Which of the following hydrocarbons is mainly used as fuel?

A.

Methylene

B.

Ethylene

C.

Methane

D.

Ethyne

Correct answer is C

No explanation has been provided for this answer.

3,259.

An organic compound reacted with bromine water to give a colourless solution. The compound is probably an?

A.

alkene

B.

alkanal

C.

alkyl

D.

alkanone

Correct answer is A

Alkenes react in the cold with pure liquid bromine, or with a solution of bromine in an organic solvent like tetrachloromethane. The double bond breaks, and a bromine atom becomes attached to each carbon. The bromine loses its original red-brown colour to give a colourless liquid.

Alkynes also react with bromine, decolorising it though not as immediate as alkenes.

3,260.

A compound commonly used for sterilization and preservation of specimens and food is

A.

ethanol

B.

benzene

C.

ether

D.

ammonia

Correct answer is A

No explanation has been provided for this answer.