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Tuesday, 16 June 2026
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Chemistry Past Questions and Answers

Topic: Separation of mixtures and purification of chemical substances

Jamb Chemistry Questions - Separation of mixtures and purification of chemical substances

Question 121:
The above diagram gives the potential energy profile of the catalyst and uncatalysed reactions of X(g) + Y(g) → XY(g). Deduce the respective activation energies in KJ of the catalysed and uncatalysed reverse reactions: XY(g) → X(g) + Y(g)
  • A 300, 500
  • B 500, 300
  • C -300, -500
  • D -500, -300
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Question 122:
The above diagram gives the potential energy profile of the catalyst and uncatalysed reactions of X(g) + Y(g) → XY(g). Deduce the respective activation energies in KJ of the catalysed and uncatalysed reverse reactions: XY(g) → X(g) + Y(g)
  • A 300, 500
  • B 500, 300
  • C -300, -500
  • D -500, -300
View Answer & Explanation
Question 123:
If in the graph above 1 dm 3 of a saturated solution of KCL is cooled from 80oC, the mass of crystals deposited will be
[K = 39, Cl = 35.5]
  • A 7.45 g
  • B 14.90 g
  • C 74.50 g
  • D 149.00 g
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Question 124:
Use the figure above to answer this question. Which of the following is NOT a monomer?
  • A A
  • B B
  • C C
  • D D
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Question 125:
Which of the following is a physical change?
  • A The bubbling of chlorine into water
  • B The bubbling of chlorine into a jar contanining hydrogen
  • C The dissolution of sodium chloride in water
  • D The passing of steam over heated iron
View Answer & Explanation