WAEC Chemistry Past Questions & Answers - Page 280

1,396.

Which of the following statements explains why tetraoxosulphate (IV) acid is reqarded as a strong acid?

A.

Tetraoxosulphate (IV) acid is dibasic

B.

the acid is concentrated

C.

the acid is complately ionized in aqueous solution

D.

tetraxosulphate (IV) ions are very reactive

E.

the acid is highly corrosive

Correct answer is C

No explanation has been provided for this answer.

1,397.

How many mole of AgNO 3 are there in 500cm3 of 0.01MAgNO3 solution?

A.

0.005 mole

B.

0.05 mole

C.

0.5 mole

D.

5 moles

E.

1 mole

Correct answer is A

No explanation has been provided for this answer.

1,398.

The following alloys contain copper except

A.

magnalium

B.

duralumn

C.

bronze

D.

brass

E.

type metal

Correct answer is A

No explanation has been provided for this answer.

1,399.

Which of the following equations represents the reaction leading to the removal of permanent hardness of water?

A.

Ca(HCO 3)2 → CaCO3 + H2O + CO2

B.

MgSO4 + Na 2CO3 + Na 2SO

C.

Ca(OH) 2 + 2HCI → CaCI 2 + 2H 2O

D.

Ca(HCO3)2 + Ca(OH)3 → 2CaCO3 + 2H2O

E.

MgSO4 + BaCI2 → MgCI2 + BaSO4

Correct answer is B

No explanation has been provided for this answer.

1,400.

In the reaction represented by the equation; 2FeCI3 + SO2 + 2H2O → 2FeCL2 + H2SO4 + 2HCI the oxidation number of sulphur changes from

A.

+2 to + 6

B.

+ 4 to + 6

C.

0 to + 6

D.

- 2 to + 4

E.

+2 to + 4

Correct answer is B

No explanation has been provided for this answer.