Search SchoolNGR

Wednesday, 13 May 2026
Register . Login

Chemistry Past Questions and Answers

Topic: Electrolysis

Jamb Chemistry Questions - Electrolysis

Question 76:
The reddish-brown rust on iron roofing sheets consists of
  • A Fe<sup style='font-size: smaller;'>3+</sup>(H<sub style='font-size: smaller;'>2</sub>O)<sub style='font-size: smaller;'>6</sub>
  • B FeO.H<sub style='font-size: smaller;'>2</sub>O
  • C Fe<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>3</sub>.3H<sub style='font-size: smaller;'>2</sub>O
  • D Fe<sub style='font-size: smaller;'>3</sub>O<sub style='font-size: smaller;'>4</sub>.2H<sub style='font-size: smaller;'>2</sub>O
View Answer & Explanation
Question 77:
In recharging a lead-acid accumulator, the reaction at the cathode can be represented as
  • A Pb<sup style='font-size: smaller;'>2+</sup><sub style='font-size: smaller;'>(aq)</sub> + SO<sup style='font-size: smaller;'>2-</sup><sub style='font-size: smaller;'>4(aq)</sub> →PbSO<sub style='font-size: smaller;'>4(s)</sub>
  • B Pb<sup style='font-size: smaller;'>2+</sup><sub style='font-size: smaller;'>(aq)</sub> + 2e<sup style='font-size: smaller;'>-</sup> →Pb<sub style='font-size: smaller;'>(s)</sub>
  • C Pb<sup style='font-size: smaller;'>2+</sup><sub style='font-size: smaller;'>(aq)</sub> + 2H<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>(l)</sub> → PbO<sub style='font-size: smaller;'>2(s)</sub> + 4H<sup style='font-size: smaller;'>+</sup><sub style='font-size: smaller;'>(aq)</sub> + 4e<sup style='font-size: smaller;'>-</sup>
  • D Pb<sub style='font-size: smaller;'>(s)</sub> → Pb<sup style='font-size: smaller;'>2+</sup><sub style='font-size: smaller;'>(aq)</sub> + 2e<sup style='font-size: smaller;'>-</sup>
View Answer & Explanation
Question 78:
If a given quantity of electricity liberates 0.65g of Zn2+, what amount of Hg2+ would be liberated by the same quantity of current?
[Zn = 65, Hg = 201]
  • A 1.00g
  • B 2.10g
  • C 4.02g
  • D 8.04g
View Answer & Explanation
Question 79:
which of the following gives a precipitate when treated with NaOH solution?
  • A AlCl<sub style='font-size: smaller;'>3</sub>
  • B NH<sub style='font-size: smaller;'>4</sub>Cl
  • C Na<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub>
  • D CH<sub style='font-size: smaller;'>3</sub>COONa
View Answer & Explanation
Question 80:
Reduction of nitroalkanes, nitrites and amides is a route for the preparation of
  • A Amines
  • B Alkenes
  • C Polymers
  • D Detergents
View Answer & Explanation