NECO Chemistry Past Questions & Answers - Page 18

86.

The pH of water is 7.

What is the pH of orange juice?

A.

7

B.

above 10

C.

below 2

D.

between 5.5 and 6.5

E.

between 7.5 and 8.5

Correct answer is D

No explanation has been provided for this answer.

87.

Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass

A.

acquire certain colours

B.

easier to melt

C.

easier to mould

D.

little brittle

E.

more transparent

Correct answer is A

No explanation has been provided for this answer.

88.

Which separation technique is routinely applied in the petroleum industry?

A.

chromatography

B.

distillation

C.

evaporation

D.

fractional crystallization

E.

fractional distillation

Correct answer is E

No explanation has been provided for this answer.

89.

Which metal is extracted from bauxite?

A.

aluminium

B.

calcium

C.

copper

D.

magnesium

E.

tin

Correct answer is A

No explanation has been provided for this answer.

90.

Why is tetraoxosulphate(VI) acid NOT used for making carbon dioxide from calcium carbonate? It is

A.

a dehydrating agent

B.

a strong acid

C.

an oxidising agent

D.

dibasic

E.

forms insoluble calcium tetraoxosulphate(Vl)

Correct answer is E

No explanation has been provided for this answer.