WAEC Chemistry Past Questions & Answers - Page 228

1,136.

AN AQUEOUS SOLUTION IS ACIDIC IF

A.

its pH value is high

B.

it s corrosive

C.

it changes the colour of litmus

D.

it has a bitter taste

E.

it contains more H3O- than OH-

Correct answer is E

No explanation has been provided for this answer.

1,137.

What is the basicity of the acid in the followed reaction? NaCO + 2CHCOOH → 2CH COONa + H2O + CO2

A.

1

B.

2

C.

3

D.

4

E.

8

Correct answer is A

No explanation has been provided for this answer.

1,138.

A mixture of NaCI(s) and CaCO3(s) is best separated by

A.

dissolution followed by filtration

B.

sublimation followed by crystallization

C.

dissolution followed by evaporation

D.

dissolution followed by crystallization

E.

sublimation followed by dissolution

Correct answer is A

No explanation has been provided for this answer.

1,139.

What volume of oxygen at s.t.p would react with carbon to form 4.40g of CO2 according to the following equation? C(s) + O2(g) → CO2(g) [O = 16; C =12; 1 mole of a gas occupies 22.4dm3 at s.t.p]

A.

0.224dm3

B.

2.24dm3

C.

4.40dm3

D.

4.48dm3

E.

22.4dm3

Correct answer is B

From the equation, C + O2 → CO2 : 22.dm3 of oxygen is required to form 44g of CO2 the volume of O2 required to produce 4.4gm is x, :. x = 44/44 X 22.4dm3

1,140.

Boyle's law can be expressed mathematically as

A.

V \(\alpha\) T (P constant)

B.

P \(\alpha\) V (T constant)

C.

P \(\alpha\) T

D.

V \(\alpha\) 1 / p(T constant)

E.

V1/T1 = / T2

Correct answer is D

The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain