The reaction occurring at the anode during the electrolysis of an aqueous solution containing Na₂SO₄ and CuSO₄ using Pt electrodes 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
At the anode (oxidation), we compare the oxidation potentials of SO₄²⁻ and H₂O. Water has a lower oxidation potential than the sulfate ion, meaning it is more easily oxidized. The oxidation of water produces oxygen gas and H⁺ ions.
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Electrochemistry describes electron transfer through oxidation and reduction, identifies oxidizing and reducing agents, and applies oxidation numbers to balance redox equations. It also covers electrode potential and the standard hydrogen electrode, which provides the reference for comparing the reduction tendencies of other electrodes.
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