BioMedical Admissions Test (BMAT) 2025 – 400 Free Practice Questions to Pass the Exam

In the copper electrolysis process, at the cathode, copper ions (Cu²⁺) undergo a reduction reaction where they gain electrons. This process transforms the positively charged copper ions into neutral copper atoms. The relevant half-reaction is:

Cu²⁺(aq) + 2e⁻ → Cu(s)

As the copper ions gain electrons from the cathode, they effectively lose their charge and deposit as solid copper. This reaction is essential in electrolysis for purifying copper, as it enables the removal of impurities from the copper ions in solution.

Other options do not accurately describe the behavior of copper ions at the cathode. While it may be tempting to think that they dissolve or remain unchanged, the critical process that occurs is the gain of electrons, leading to the formation of solid copper. This fundamental electrochemical reaction is key to achieving the desired outcomes in processes that involve copper electrolysis, such as metal plating or purification.