Electrolysis - Chemistry Jamb Past Questions and Answers

Question 21 :

• JAMB 1985

Which of the following conduct electricity?

A. Sulfur
B. Graphite
C. Diamond
D. Red phosphorus
E. Yellow phosphorus

Question 22 :

• JAMB 1986

How many coulombs of electricity are passed through a solution in which 6.5 amperes are allowed to run for 1.0 hour?

A. 3.90 x 10² coulombs
B. 5.50 x 10³ coulombs
C. 6.54 x 10³ coulombs
D. 2.34 x 10⁴ coulombs

Question 23 :

• JAMB 1986

Which of these represents a redox reaction?

A. AgNO₃ + NaCl → AgCAl + NaNO₃
B. H₂S + Pb(NO₃) → PbS + 2HNO₃
C. CaCO₃ → CaO + CO₂
D. Zn + 2HCl → ZnCl₂ + H₂

Question 24 :

• JAMB 1986

In the electrolysis of aqueous solution of K₂SO ₄ in the above cell, which species migrate to the anode?

A. SO^2-OH ^-
B. K ⁺ and SO ₄^2-
C. OH and HO
D. H₃O ⁺ and K

Question 25 :

• JAMB 1988

Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution?

A. Cu²⁺ + 2e^- → Cu(s)
B. 2Cl^- -2e → Cl₂
C. Cu_(s) -2e → Cu²⁺_(aq)
D. Cu²⁺_(aq) + 2Cl^-_(aq) → CuCl_2(aq)