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WAEC Chemistry Past Questions & Answers - Page 70

346.

A compound has an empirical formular CH2O and molecular mass of 90.

[H = 1.00, C = 12.0, O = 16.0]

A.

C4H10O2

B.

C3H10O2

C.

C3H6O3

D.

C2H2O4

Correct answer is C

(CH2O)n = 90; (12 + (1 x 2) + 16)n = 90
(12 + 2 + 16)n = 90; 30n = 90; n = 9030; n = 3
(CH2O)3 = Molecular formula ; = C3H6O3

347.

The complete hydrogenation of benzene gives

A.

Cyclohexene

B.

Cyclohexane

C.

Hexene

D.

Hexane

Correct answer is B

No explanation has been provided for this answer.

348.

Which of the following metals is the strongest reducing agent?

A.

Sodium

B.

Silver

C.

Potassium

D.

Copper

Correct answer is C

No explanation has been provided for this answer.

349.

Consider the following reaction equation:
CuO(s) + H2(g) Cu(s) + H2O(1)

Which substance is oxidized?

A.

Cu

B.

CuO

C.

H2

D.

H2O

Correct answer is C

No explanation has been provided for this answer.

350.

Which of the following statements about an electrochemical cell is correct? Oxidation occurs

A.

At the anode

B.

At the cathode

C.

Through the salt bridge

D.

In the aqueous solution

Correct answer is A

No explanation has been provided for this answer.