WAEC Chemistry Past Questions & Answers - Page 136

676.

Which of the following statements about a molar solution is correct? it

A.

is a supersaturated solution

B.

cannot dissolve more of the solute at that temperature

C.

contains any amount of solute in a given volume of solution

D.

contains one mole of the solute in 1 dm3 of solution

Correct answer is D

No explanation has been provided for this answer.

677.

The number of atoms in one mole of a substance is equal to the

A.

mass number

B.

oxidation number

C.

atomic number

D.

avogadro number

Correct answer is D

No explanation has been provided for this answer.

678.

What is the amount of magnesium that would contain 1.20 x 1024 particles? [Mg = 24, Avogadro's constant = 6.02 x 1023]

A.

0.5 moles

B.

2.0 moles

C.

12.0 moles

D.

24.0 moles

Correct answer is B

No explanation has been provided for this answer.

679.

Consider the reaction represented by the following equation: xKMnO 4(aq) + ySO2(g) + zH2O(I) → K 2SO4(AQ) + 2MnSO4(aq) + 2H2SO x,y and z are respectively

A.

2,5 and 2

B.

2,2 and 5

C.

5, 1 and 2

D.

1, 5 and 2

Correct answer is A

No explanation has been provided for this answer.

680.

The volume occupied by 17g of H2S at s.t.p. is [H = 1.00, S = 32.0, Molar volume = 22.4 dm3]

A.

11.2dm 3

B.

17.0 dm3

C.

34.0dm 3

D.

44.8dm 3

Correct answer is A

No explanation has been provided for this answer.