WAEC Chemistry Past Questions & Answers - Page 210

1,046.

An iron nail placed in a solution copper (ll) tetraoxosulphate (VI) is soon covered with a deposit of copper which of the following equations represents the reactions ?

A.

Fe 2+ (aq) + Cu(s) → Fe 3+ + Cu 2+ (aq)

B.

Fe 2+ (aq) + Cu(s) → Fe(s) + Cu2+ (aq)

C.

Fe (s) + Cu2+ (aq) → Fe2+(aq) + Cu2+ (aq)

D.

Fe(s) + Cu2+ → Fe2+(aq) + Cu(s)

Correct answer is D

No explanation has been provided for this answer.

1,047.

What is the value of x in the following equation? Cr2O72- + 14H+ + xe- → 2Cr3+ + 7H2O

A.

1

B.

6

C.

8

D.

12

Correct answer is B

No explanation has been provided for this answer.

1,048.

Which of the following will displace copper from a solution of copper (ll) salt?

A.

Aluminium ions

B.

Magnesium

C.

Silver

D.

Zinc ions

Correct answer is B

No explanation has been provided for this answer.

1,049.

A finely divided from of a metal burns more readily in air than the rod from because the rod has

A.

higher molar mass

B.

smaller surface area

C.

protective oxide coating

D.

diferent chemical properties

Correct answer is B

No explanation has been provided for this answer.

1,050.

What is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO2 + O2 ⇌ 2SO3; ∆H = - xKJmol-1

A.

Decreases the value of ∆H

B.

Increases the collision rate of reactant particles

C.

Shifts equilibrium position to the right

D.

Reduces the time for attainment of equilibrium

Correct answer is D

In the contact process above; a temperature of about 500ºC and use of Vanadium(V)Oxide catalyst increase the reaction rate and enable equilibrium to be reached in a shorter time.