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.

521.

Which of the following will give a precipitate with an aqueous solution of copper (I) chloride?

A.

But-2-ene

B.

But-1-ene

C.

But-2-yne

D.

But-1-yne

Correct answer is D

No explanation has been provided for this answer.

522.

A secondary alkanol can be oxidized to give an?

A.

alkanone

B.

alkyne

C.

alkanoic acid

D.

alkanal

Correct answer is A

Secondary alkanols (alcohols) can be oxidised to alkanones (ketones)

523.

Petroleum is a non-renewable source of energy because it

A.

is formed naturally

B.

is cheap

C.

can be recycled after use

D.

cannot be regenerated once used up

Correct answer is D

No explanation has been provided for this answer.

524.

A primary alkanol has a molecular mass of 60. What is the structural formula of the compound? [C= 12.0, H= 1.0, O= 16.0)

A.

A

B.

B

C.

C

D.

D

Correct answer is B

Alkanols have the formula \(C_{n}H_{2n+1}OH\).

⇒  \( 12n + (1\times (2n+1)) + 16.0 + 1.0 = 60\)

= (14n +18 = 60\)

\(n = \frac{60-18}{14} = \frac{42}{14} = 3\)

Hence, the alkanol is gotten by putting n=3,

=\(C_{3}H_{7}OH\)

525.

The real harmful effect of the release of chlorofluorocarbons into the atmosphere is that it eventually causes

A.

excessive ultraviolet light from the sun to reach the earth surface

B.

excessive release of infrared light from the sun to the earth surface

C.

corrosive effect of the chemicals on humans and animals

D.

acidic effect of chemicals on humans

Correct answer is A

Chlorofluorocarbons are harmful to environment and living beings because it increases greenhouse gases in the environment which results in forming holes in the ozone layer.. And if this happens it will cause to an increase in the ultraviolet rays exposer, and which will make the earth's surface much hotter than usual.