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Thursday, 14 May 2026
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Chemistry Past Questions and Answers

Topic: Electrolysis

Jamb Chemistry Questions - Electrolysis

Question 101:
A sample of orange juice is found to have a PH of 3.80. What is the concentration of the hydroxide ion in the juice?
  • A 1.6 \(\times\) 10<sup style='font-size: smaller;'>-4</sup>
  • B 6.3 \(\times\) 10<sup style='font-size: smaller;'>-11</sup>
  • C 6.3 \(\times\) 10<sup style='font-size: smaller;'>-4</sup>
  • D 1.6 \(\times\) 10<sup style='font-size: smaller;'>-11</sup>
View Answer & Explanation
Question 102:
Incomplete oxidation of ethanol yields
  • A CH<sub style='font-size: smaller;'>3</sub>COOH
  • B CH<sub style='font-size: smaller;'>3</sub>COCH<sub style='font-size: smaller;'>3</sub>
  • C CH<sub style='font-size: smaller;'>3</sub>CH<sub style='font-size: smaller;'>2</sub>OCH<sub style='font-size: smaller;'>2</sub>CH<sub style='font-size: smaller;'>3</sub>
  • D CH<sub style='font-size: smaller;'>2</sub>CHO
View Answer & Explanation
Question 103:
The reddish—brown rust on ion 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>.2H2<sub style='font-size: smaller;'>2</sub>O
View Answer & Explanation
Question 104:
A correct electrochemical series can be obtained from Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging
  • A Al and Mg
  • B Zn and Fe
  • C Zn and Pb
  • D Pb and H
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Question 105:
An aqueous solution of a metal salt, M. gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia Therefore the cation in M is
  • A Zn
  • B Ca
  • C Al
  • D Po
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