Question

An aqueous solution of CuSO4 is electrolyzed using platinum electrodes.
Which of the following will be observed at the cathode?

• A. Copper metal is deposited.
• B. Hydrogen gas is evolved.
• C. Oxygen gas is evolved.
• D. Copper dissolves.

Hint:

During electrolysis, at the cathode, reduction occurs (metal deposition or hydrogen evolution). At the anode, oxidation occurs (oxygen evolution or metal dissolution).

Answer 1

The Correct Option is A

During the electrolysis of aqueous CuSO4, copper metal plates the cathode. This occurs as copper ions (Cu\(^{2+}\)) undergo reduction to copper metal (Cu) at the cathode. The cathodic half-reaction is: \[ Cu^{2+} + 2e^- \rightarrow Cu \] While oxygen gas is produced at the anode, the question specifically concerns the cathode, where copper deposition takes place. Therefore, option (A) is the correct choice.