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JAMB Chemistry 2002 Question 14

Question 14

Redox Reactions

Cu2S(s) + O2(g) → 2Cu(s) + SO2(g)
What is the change in the oxidation number of copper in the reaction above?

  1. A.+1 to 0
  2. B.0 to +2
  3. C.+2 to +1
  4. D.0 to +1
Show the answer and explanation

Answer: A (+1 to 0)

Explanation

In Cu2S sulphur is −2, so each copper is +1. Free copper metal is 0, so copper changes from +1 to 0.