Jamb Chemistry 1994 Past Questions and Answers

Question 21:

• JAMB 1994

What volume of oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?
(Molar volume of gas = 22.4 dm³, F = 96,500 C mol^-)

A. 22.4 dm³
B. 11.2 dm³
C. 1.12 dm³
D. 0.560 dm³

Question 22:

• JAMB 1994

Crude copper could be purified by the electrolysis of concentrated copper (II) chloride if the crude copper is?

A. Made both the anode and the cathode
B. Made the cathode
C. Made the anode
D. Dissolved in the solution

Question 23:

• JAMB 1994

H^- + H_2(I)O → H_2(g) + OH^-_(aq). From the equation above, it can be inferred that the?

A. Reaction is a double decomposition
B. Hydride ion is a reducing agent
C. Hydride ion is an oxidizing agent
D. Reaction is neutralization

Question 24:

• JAMB 1994

An anhydride is an oxide of non-mental?

A. Which will not dissolve in water
B. Whose solution in water has a pH greater than 7
C. Whose solution in water has a pH less than 7
D. Whose solution in water has a pH of 7

Question 25:

• JAMB 1994

MnO_4(aq) + 8H + _(aq) + 5Fe²⁺ → Mn^2+(aq) + 4H₂O_(I). The oxidation number of manganese in the above reaction changed from?

A. +7 to +2
B. +6 to +2
C. +5 to +2
D. +4 to +2