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.

811.

A consequences of global warming is

A.

Air pollution

B.

Flooding

C.

Increased humidity

D.

Water pollution

Correct answer is B

Global warming is a gradual increase in the earth’s temperature generally due to the greenhouse effect caused by increased levels of carbon dioxide,  CFCs, and other pollutants., consequences of global warming include: Seasonal/climate change, Rising oceans, Increase in flooding occurrences. Melting ice caps or polar ice. Increase in the average temperature of the world.

812.

Which of the following sources of energy contributes to green-house effect?

A.

Natural gas

B.

Nuclear

C.

Wind

D.

Solar

Correct answer is A

No explanation has been provided for this answer.

813.

Consider the following reaction equation
C2H4(g) + 3O2(g) \(\to\) 2CO2(g) + 2H2O(l).

The volume of oxygen at s.t.p that will be required to burn 14g of ethene is
[C2H4 = 28; Molar volume of gas at s.t.p = 22.4dm3

A.

64.2dm3

B.

33.6dm3

C.

11.2dm3

D.

3.73dm3

Correct answer is B

C2H4(g) + 3O2(g) \(\to\) 2CO2(g) + 2H2O(l)

1 mole of ethene required 3 moles of O2
28g of ethene required 3 x 22.4dm3 of O2

14g will require \(\frac{14 \times 3 \times 22.4dm^3}{28}\)

= 33.6dm3

814.

Which of the following compounds is/are secondary alkanols?

i) CH3CH(CH3)CH3OH
ii) CH3CH2CH(OH)CH3
iii) CH3C(OH)(CH3)CH3

A.

I only

B.

II only

C.

I and III only

D.

II and III only

Correct answer is B

No explanation has been provided for this answer.

815.

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

The ethanol (alcohol content) of the wine, is oxidized, by the oxygen in the air into ethanoic acid.