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Saturday, 23 May 2026
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Chemistry Past Questions and Answers

Jamb 1995 Chemistry Questions

Question 21:
2CL-(aq) → CI2(g) + 2e-(aq). The above half-cell reaction occuring at the anode during the electrolysis of dilute ZnCI2 solution is?
  • A Ionization
  • B Oxidation
  • C Reduction
  • D Recombination
View Answer & Explanation
Question 22:
Which of the following is a redox reaction?
  • A KCI<sub style='font-size: smaller;'>(aq)</sub> + H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4(aq)</sub> → KHSO<sub style='font-size: smaller;'>4(aq)</sub> + HCI<sub style='font-size: smaller;'>(aq)</sub>
  • B 2FeBr<sub style='font-size: smaller;'>2(aq)</sub> + Br<sub style='font-size: smaller;'>4(aq)</sub> → 2FeBr<sub style='font-size: smaller;'>3(aq)</sub>
  • C 3AgNO<sub style='font-size: smaller;'>(aq)</sub> + FeCl<sub style='font-size: smaller;'>3(aq)</sub> → 3AgCl<sub style='font-size: smaller;'>(aq)</sub> + Fe(NO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>3(aq)</sub>
  • D H<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3(aq)</sub> → H<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>(I)2-</sub> + CO<sub style='font-size: smaller;'>2(g)</sub>
View Answer & Explanation
Question 23:
Cr2O72-(aq) + 14H+(aq) + 6l-(aq) → 2Cr3+(aq) + 3l(g) + 7H2O(I).
The change in the oxidation number of oxygen in the equation above is?
  • B 1
  • C 2
  • D 7
View Answer & Explanation
Question 24:
If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?
  • A Low temperatures
  • B High temperatures
  • C All temperatures
  • D All pressures
View Answer & Explanation
Question 25:
Which of the following processes leads to increase in entropy?
  • A Mixing a sample of NaCl and sand
  • B Condensation of water vapour
  • C Boiling a sample of water
  • D Cooling a saturated solution
View Answer & Explanation