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Thursday, 11 June 2026
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Chemistry Past Questions and Answers

Jamb 2019 Chemistry Questions

Question 91:
Which of the following statements about catalyst is false?
  • A Biological catalysts are called enzymes
  • B Catalyst do not appear in the balanced equation
  • C Catalyst reduce the activation energy for a reaction
  • D Catalysts do not alter the mechanism of the reaction and never appear in the rate low
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Question 92:
Which of the following does not support the fact that air is a mixture?
  • A The constituents of air are in a fixed proportion by mass
  • B It cannot be represented with a chemical formula
  • C The constituents of air can be separated by physical by physical means
  • D None of the above
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Question 93:
What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?
  • A Fractional crystallization
  • B Fractional distillation
  • C Filtration
  • D Evaporation
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Question 94:
At 27°C, 58.5g of sodium chloride is present in 250cm\(^3\) of a solution. The solubility of sodium chloride at this temperature is?
(molar mass of sodium chloride = 111.0gmol\(^{-1}\))
  • A 2.0 moldm\(^{-3}\)
  • B 0.25 moldm\(^{-3}\)
  • C 1.0 moldm\(^{-3}\)
  • D 0.5 moldm\(^{-3}\)
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Question 95:
Which of the following properties increases from left to right along the period but decreases down the group in the Periodic Table?
i. Atomic Number ii. Ionization energy iii. Metallic character iv. Electron affinity
  • A Ii and iii only
  • B Ii and iv only
  • C Iii and iv only
  • D I and ii only
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