Waec Chemistry 2001 Past Questions and Answers

Question 21:

• WAEC 2001

What is oxidized in the reaction represented by the following equation? 3CU + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O

A. Oxygen
B. Hydrogen
C. Nitrogen
D. Copper

Question 22:

• WAEC 2001

Which of the following substances decomposes when an electric current is passed through it?

A. Glucose solution
B. Zinc rod
C. Hydrochloric acid
D. Tetrachlormethane

Question 23:

• WAEC 2001

A concentrated solution containing H⁺, Cu²⁺,OH^- and CI^- was electrolysed using platiunm electrodes which of the ions will be discharged at the cathods?

A. H⁺
B. Cu²⁺
C. OH^-
D. CI^-

Question 24:

• WAEC 2001

Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible?

A. S + P⁺ → P + S ⁺
B. Q + S⁺ → S + Q⁺
C. R + P⁺ → P + R⁺
D. S + Q⁺ → Q + S⁺

Question 25:

• WAEC 2001

In the electrolysis of CuSO_4(aq) using copper electrodes, the reaction at the anode is

A. Discharge of SOsub>4 ^2-
B. Discharge of OH^-
C. Dissolution of copper electrode
D. Evolution of oxygen