WAEC Past Questions and Answers - Page 1688

8,436.

Mould growth on cereal grains stored in damp conditions is caused by

A.

Bacterium

B.

Fungus

C.

Virus

D.

Nematode

Correct answer is B

No explanation has been provided for this answer.

8,437.

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.

8,438.

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.

8,439.

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.

8,440.

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.