WAEC Chemistry Past Questions & Answers - Page 158

786.

The mass spectrometer can be used to measure mass of

A.

an atom

B.

an electron

C.

a proton

D.

a neutron

Correct answer is A

No explanation has been provided for this answer.

787.

Which of the these metals will not liberate hydrogen from dilute HCI?

A.

Copper

B.

Iron

C.

Magnesium

D.

Zinc

Correct answer is A

No explanation has been provided for this answer.

788.

What volume will 0.5 g of H2 occupy at s.t.p? [H = 1; 1 mole of a gas occupy 22.4 dm3 at s.t.p.]

A.

2.24 dm3

B.

5.60dm3

C.

11.20dm3

D.

44.80dm3

Correct answer is B

No explanation has been provided for this answer.

789.

Pig-iron is brittle because it contains

A.

a high percentage of carbon as impurity

B.

calcium trioxosilicate (IV)

C.

unreacted haematite

D.

undecomposed limestone

Correct answer is A

No explanation has been provided for this answer.

790.

The following substances are heavy chemicals except

A.

sodium trioxocarbonate (IV)

B.

tetraoxosulphate (VI) acid

C.

lead (lV) tetraethyl

D.

sodium hydroxide

Correct answer is C

No explanation has been provided for this answer.