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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.

131.

Which of the following sketches is a graphical representation of Boyle's law?

A.

A

B.

B

C.

C

D.

D

Correct answer is C

Boyles law states that the volume of a given mass of gas is inversely proportional to pressure at constant temperature.

132.

Which of the following scientists formulated the law of conservation of mass?

A.

A. Lavoisier

B.

J. Dalton

C.

R. Boyle

D.

J. Proust

Correct answer is A

Law of conservation of mass was given by Antoine Lavoisier in 1744. According to this law, "Matter can neither be created nor destroyed in a chemical reaction".

133.

The first definition of an element was made by

A.

J. Dalton.

B.

A. Lavoisier.

C.

R. Boyle.

D.

J. J. Thompson.

Correct answer is C

The word element was first given by Rebert Boyle. It is defined as the simplest chemical substance that cannot be broken down during a chemical reaction

134.

Charcoal is used in the decolourization of sugar because of its

A.

absorption property.

B.

amorphous property.

C.

oxidizing property.

D.

adsorption property.

Correct answer is D

Wood charcoal is used to decolourise sugar because it has a highly porous structure, providing a large surface area for adsorption. Therefore, it adsorbs coloured material from sugar.

135.

If the molar mass of X(HCO3)2 is 162 g mol1, determine the relative atomic mass of X.
[H = 1.0, C = 12.0, 0 = 16.0]

A.

40

B.

48

C.

61

D.

101

Correct answer is A

Molar mass of X(HCO3)2 = X+(1+12+(16*3))2=162
=X + (13+48)2=162
X + 122=162
X=162-122
X=40