WAEC Chemistry Past Questions & Answers - Page 234

1,166.

What is the value of x in the following equation? MnO- 4 + 4H+ + xe- → MnO 2 + 2H2O

A.

2

B.

3

C.

4

D.

7

E.

8

Correct answer is B

No explanation has been provided for this answer.

1,167.

From the following equations, what is the order of decreasing reactivity of X, Y and Z? Y (s) + X2+(aq) → Y2+(aq) + X(s) X(s) + Z2+(aq) → X2+(aq) + Z(s)

A.

X>Y>Z

B.

Y > X > Z

C.

Z > Y > X

D.

Y > Z > X

E.

X > Z > Y

Correct answer is B

No explanation has been provided for this answer.

1,168.

The common feature of reactions at the anode is that

A.

electrons are consumed

B.

oxidation is involved

C.

ions are reduced

D.

the electrode dissolves

E.

the electrolyte is diluted

Correct answer is B

No explanation has been provided for this answer.

1,169.

What quantity of electrons (in mole) is lost when one mole of iron (ll) ions is oxidized to iron (lll) ions?

A.

5 mole

B.

4 mole

C.

3 mole

D.

2 mole

E.

1 mole

Correct answer is E

No explanation has been provided for this answer.

1,170.

Which of the following ions will migrate to the cathode during electrolysis?

A.

Zinc ions

B.

Chloride ions

C.

Sulphide ions

D.

Tetraoxosulphate (Vl) ions

E.

Trioxonitrate (V) ions

Correct answer is A

No explanation has been provided for this answer.