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.

1,371.

The reagent that can be used to distinguish ethene from ethyne is

A.

ammoniacal silver trioxonitrate (V) solution

B.

Benedict solution

C.

bromine water

D.

Fehling's solution

Correct answer is A

To distinguish between ethene and ethyne: i Add a few drops of ammonical copper(I) chloride to each of ethylene (ethene) and acetylene (ethyne). No change will be observed in the case of ethylene (ethene) but in the case of acetylene (ethyne), a red precipitate of copper acetylide is formed. similar result

ii) When ammoniacal Silver Nitrate (AgNO3) is added to Ethyne then it gives white precipitates. But when Ammoniacal silver nitrate is added to Ethene then no reaction occurs and no precipitates obtain.

1,372.

The compound that makes palm wine taste sour after exposure to the air for few days is

A.

ethanol

B.

ethanoic acid

C.

methanol

D.

methanoic acid

Correct answer is A

No explanation has been provided for this answer.

1,373.

When bromine is added to ethene at room temperature, the compound formed is

A.

1,1 - dibromoethane

B.

1,2 - dibromoethene

C.

1,1 - dibromoethene

D.

1,2 - dibromoethane

Correct answer is D

Ethene is an alkene, meaning it has a carbon to carbon double bond. When Bromine is added, an addition reaction occurs forming 1,2 dibromoethane.

C2H4 + Br2 -> C2H4Br2

1,374.

The following substances are examples of addition polymer except

A.

nylon

B.

perspex

C.

polyethene

D.

polychloroethene

Correct answer is A

Every option, except nylon (which is a condensation polymer), is an addition polymer.

1,375.

Which of the following separation techniques would show that black ink is a mixture of chemical compounds?

A.

Crystallization

B.

Chromatography

C.

Filtration

D.

Sublimation

Correct answer is B

No explanation has been provided for this answer.