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Thursday, 11 June 2026
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Chemistry Past Questions and Answers

Jamb 2019 Chemistry Questions

Question 101:
Which of the following describes the chemical property of acids?
  • A None of the above
  • B Acid + XCO\(_3\) \(\to\) Salt + H\(_2\)O + NH\(_3\)
  • C Acid + NaOH \(\to\) Normal salt + CO\(_2\)
  • D Acid + X\(_n\)CO\(_3\) \(\to\) Salt + H\(_2\)O + CO\(_2\)
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Question 102:
Which of the following pairs cannot be represented with a chemical formula?
  • A Air and bronze
  • B Bronze and sodium chloride
  • C Copper and sodium chloride
  • D Caustic soda and washing soda
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Question 103:
Consider the equation below:
Cr\(_2\)O\(_7 ^{2-}\) + 6Fe\(^{2+}\) + 14H\(^{+}\) \(\to\) 2Cr\(^{3+}\) + 6Fe\(^{3+}\) + 7H\(_2\)O.
The oxidation number of chromium changes from
  • A +5 to +3
  • B +6 to +3
  • C -2 to +3
  • D +7 to +3
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Question 104:
Which of the following is a physical change?
  • A Exposing white phosphorus to air
  • B Burning kerosene
  • C Dissolving calcium in water
  • D Freezing ice cream
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Question 105:
In the reaction between sodium hydroxide and tetraoxosulphate (VI) solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralize 10cm\(^3\) of 1.25 molar tetraoxosulphate (vi) acid?
  • A 25cm\(^3\)
  • B 10cm\(^3\)
  • C 20cm\(^3\)
  • D 50cm\(^3\)
View Answer & Explanation