Question

During the electrolysis of dilute copper(I) sulfate solution using carbon electrodes, ions are selectively discharged at the anode and cathode. Which of the following represents what you would observe taking place at the CATHODE?

A. a red-brown solid depositing on the electrode
B. effervescence and the evolution of a colorless gas
C. effervescence and the evolution of a brown gas
D. a gray-colored solid at the bottom of the container holding the electrolyte

Answer 1

At the cathode of an electrolysis of copper(I) sulfate solution, a red-brown solid copper metal deposits on the electrode as copper ions are reduced.

Step-by-step explanation:

During the electrolysis of dilute copper(I) sulfate solution using carbon electrodes, what you would observe taking place at the cathode is a red-brown solid depositing on the electrode. This happens because at the cathode, reduction occurs; copper ions (Cu2+) gain electrons (e-) and are reduced to copper metal (Cu0), which deposits onto the electrode. The relevant half-reaction is represented by the equation: Cu2+ (aq) + 2e- → Cu0 (s).