WAEC Chemistry Past Questions & Answers - Page 258

1,286.

Zinc displaces copper from an aqueous solution of copper (ll) salt because

A.

copper is a transition element

B.

copper is a moderately reactive metal

C.

Zinc and copper have reducing prperties

D.

zinc is more reactive than copper

E.

zinc reacts with both acids and alkalis

Correct answer is D

No explanation has been provided for this answer.

1,287.

When ammonium chloride is dissolved in water in a test tube, the tube feels colder showing that

A.

the solution is unsaturated

B.

sublimation has ocurred

C.

ammonia gas is evolved

D.

the process is endothermic

E.

condensation has occurred

Correct answer is D

No explanation has been provided for this answer.

1,288.

The product of the reaction between ethanol and excess acidified K2Cr2O2 is

A.

ethanal

B.

ethylethanoate

C.

ethanoic acid

D.

ethyne

E.

ethanedioic acid

Correct answer is C

No explanation has been provided for this answer.

1,289.

Which of the following is correct about the electrons in the 1s orbital? They

A.

have the same spin

B.

are easier to remove than those in the 2p orbital

C.

are closest to the nucleus

D.

have the same energy as those in the 2s orbital

E.

have different magnetic quantum numbers

Correct answer is C

No explanation has been provided for this answer.

1,290.

Which of the following gases are diatomic except

A.

nitrogen

B.

helium

C.

hydrogen

D.

fluorine

E.

oxygen

Correct answer is B

No explanation has been provided for this answer.