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

During copper electrolysis, particularly in the refining process, impurities present in copper anode dissolve into the electrolyte solution but do not remain free or in an ionic state as pure copper does. Instead, as the electrolysis proceeds, these impurities are typically precipitated and collected as a sludge at the anode, where the copper dissolves.

The anodic reaction involves the oxidation of copper metal to copper ions, which go into the solution. Impurities, which can include metals like nickel, zinc, silver, and gold, do not undergo the same oxidation. Instead, they often remain solid due to their different electrochemical properties and tend to aggregate and settle. This sludge can then be carefully removed to keep the refining process efficient and maintain the quality of the deposited pure copper at the cathode.

Thus, the process ensures that the copper that is deposited at the cathode is of high purity while facilitating the removal of impurities from the system.