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Sunday, 14 June 2026
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Chemistry Past Questions and Answers

Waec Chemistry Questions

Question 1421:
Chemical reactions occurs when the colliding reactants have energy that is
  • A Less than the activation energy
  • B Greater than the activation energy
  • C Greater than the energy of the product
  • D Less than the energy of effective collision
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Question 1422:
The common feature of reactions at the anode is that
  • A Electrons are consumed
  • B Ions are reduced
  • C Oxidation is involved
  • D The electrode dissolves
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Question 1423:
Consider the following reaction equation: \(2NO_{(g)} + O_{{2}{(g)}} \to 2NO_{{2}{(g)}}\). What is the change in the oxidation number of nitrogen?
  • A +2 to 0
  • B +2 to -2
  • C +2 to +4
  • D +4 to +2
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Question 1424:
Which of the following factors characterize members of the same homologous series?
  • A The chemical property change gradually throughout the series
  • B Physical properties of members are similar
  • C They have the same molecular formular
  • D Successive members undergo changes in molecular formula by \(CH_{2}\)
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Question 1425:
Calculate the mass of copper deposited if a current of 0.45A flows through \(CuSO_{4}\) solution for 1hour 15mins. [Cu=64.0, S= 32.0, O =16.0, 1F= 96500C]
  • A 6.40g
  • B 0.67g
  • C 0.64g
  • D 0.45g
View Answer & Explanation