Search SchoolNGR

Sunday, 21 June 2026
Register . Login

Chemistry Past Questions and Answers

Topic: Electrolysis of dilute H₂SO₄

Jamb Chemistry Questions - Electrolysis of dilute H₂SO₄

Question 6:
A concentrated solution containing H+, Cu2+, OH- and Cl- was electrolyzed using platinum electrodes.
The ion that will be discharged at the cathode is
  • A Cu<sup style='font-size: smaller;'>2+</sup>
  • B Cl<sup style='font-size: smaller;'>-</sup>
  • C H<sup style='font-size: smaller;'>+</sup>
  • D OH<sup style='font-size: smaller;'>-</sup>
View Answer & Explanation
Question 7:
Zinc and carbon rods are used as anode and cathode respectively in a
  • A Leclanche cell
  • B Lead accumulator
  • C Daniel cell
  • D Voltaic cell
View Answer & Explanation
Question 8:
In the electrolysis of CuSO4(g) using platinum electrodes, the reaction at the anode is
  • A 4H<sup style='font-size: smaller;'>+</sup> + 4e<sup style='font-size: smaller;'>-</sup> → 2H<sub style='font-size: smaller;'>2</sub>
  • B 4OH<sup style='font-size: smaller;'>-</sup> - 4e<sup style='font-size: smaller;'>-</sup> → 2H<sub style='font-size: smaller;'>2</sub>O + O<sub style='font-size: smaller;'>2</sub>
  • C 2OH - 2e<sup style='font-size: smaller;'>-</sup> → 2OH
  • D 2OH<sup style='font-size: smaller;'>-</sup> + 2OH<sup style='font-size: smaller;'>-</sup> → 2H<sub style='font-size: smaller;'>2</sub>O + O<sub style='font-size: smaller;'>2</sub>
View Answer & Explanation
Question 9:
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 10:
Cathode rays causes an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays
  • A Are positively charged
  • B Are negatively charged
  • C Have mass
  • D Travel in straight lines
View Answer & Explanation