Jamb Chemistry 1995 Past Questions and Answers

Question 21:

• JAMB 1995

2CL^-_(aq) → CI_2(g) + 2e^-(aq). The above half-cell reaction occuring at the anode during the electrolysis of dilute ZnCI₂ solution is?

A. Ionization
B. Oxidation
C. Reduction
D. Recombination

Question 22:

• JAMB 1995

Which of the following is a redox reaction?

A. KCI_(aq) + H₂SO_4(aq) → KHSO_4(aq) + HCI_(aq)
B. 2FeBr_2(aq) + Br_4(aq) → 2FeBr_3(aq)
C. 3AgNO_(aq) + FeCl_3(aq) → 3AgCl_(aq) + Fe(NO₃)_3(aq)
D. H₂CO_3(aq) → H₂O_(I)2- + CO_2(g)

Question 23:

• JAMB 1995

Cr₂O₇^2-_(aq) + 14H⁺_(aq) + 6l^-_(aq) → 2Cr³⁺_(aq) + 3l_(g) + 7H₂O_(I).
The change in the oxidation number of oxygen in the equation above is?

B. 1
C. 2
D. 7

Question 24:

• JAMB 1995

If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?

A. Low temperatures
B. High temperatures
C. All temperatures
D. All pressures

Question 25:

• JAMB 1995

Which of the following processes leads to increase in entropy?

A. Mixing a sample of NaCl and sand
B. Condensation of water vapour
C. Boiling a sample of water
D. Cooling a saturated solution