The reaction occurring at anode when the electrolysis of an aqueous solution containing Na2SO4 and CuSO4 is done using Pt electrode is:
Correct answer: C. oxidation of water to form oxygen gas and hydrogen ions.
- A. Oxidation of copper ions to form copper oxide
- B. Oxidation of sulfate ions to form sulfur trioxide
- C. oxidation of water to form oxygen gas and hydrogen ions.
- D. Oxidation of chloride ions to form chlorine gas
Explanation
In the electrolysis of an aqueous solution containing Na2SO4 and CuSO4 with a Pt electrode, water is oxidized at the anode to form oxygen gas and hydrogen ions. This occurs because water has a lower oxidation potential compared to sulfate ions, making it more likely to be oxidized. The reaction is:2H2O(l) → O2(g) + 4H+ + 4e-Other options are incorrect as copper ions are reduced at the cathode, sulfate ions are less likely to oxidize than water, and chloride ions are not relevant to this electrolysis setup.
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