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JAMB Chemistry 1987 Question 24

Question 24

Redox Reactions

In the reaction: 3CuO + 2NH3 → 3Cu + 3H2O + N2 how many electrons are transferred for each mole of copper produced?

  1. A.4.0 × 10−23
  2. B.3.0 × 10−23
  3. C.1.2 × 1024
  4. D.6.0 × 1024
Show the answer and explanation

Answer: C (1.2 × 1024)

Explanation

Each Cu2+ gains 2 electrons to become Cu. One mole of Cu therefore needs 2 × 6.02 × 1023 = 1.2 × 1024 electrons.