WAEC Chemistry Past Questions & Answers - Page 264

1,316.

Which of the following separation is routinely applied in the petroleum industry

A.

Filtration

B.

Chromatography

C.

Evaporation

D.

Fractional crystallization

E.

Fractional distillation

Correct answer is E

No explanation has been provided for this answer.

1,317.

Which of the following accounts for the difference in the mode of conduction of electricity by metals and aqueous salt solutions?

A.

Electrons are present in metals but not in salt solutions

B.

Metals are conductors while salts are electrolytes

C.

Electricity is carried by mobile elrctrons in metals but by ions is aqueous salt solution

D.

salts ionize in aqueous solutions while metals do not

E.

Metals are reducing agents while salts are not

Correct answer is C

No explanation has been provided for this answer.

1,318.

A dye is suspected to have contaminated a lollipop. Which of the following is the best method by which the contaminant may be isolated?

A.

Fractional distillational

B.

Recrystallization

C.

Filtration

D.

Paper chromatography

E.

Evaporation

Correct answer is D

No explanation has been provided for this answer.

1,319.

What is the value of n in the following equation? XO-4 +8H + + ne- → X2 + + 4H2O

A.

2

B.

3

C.

4

D.

5

E.

6

Correct answer is D

No explanation has been provided for this answer.

1,320.

Which of the following groups contains entirely linear molecules?

A.

H 2NH3O 2

B.

CO2NH 3 2

C.

H 2CH4N2

D.

CO2H2N2

E.

CH 4O 2CO 2

Correct answer is D

No explanation has been provided for this answer.