In electrolytic refining of copper, the electrolyte is a solution of

In the electrolytic refining of copper, the process involves the purification of impure copper using an electrolytic cell. The anode consists of a block of impure copper, while the cathode is a thin strip of pure copper. The electrolyte used is a solution of acidified copper sulphate. During electrolysis, copper ions from the anode dissolve into the electrolyte, and an equivalent amount of pure copper from the electrolyte is deposited onto the cathode. The addition of sulphuric acid to the copper sulphate solution increases the conductivity of the electrolyte and prevents the hydrolysis of copper salts. While copper sulphate is a common salt mentioned in chemical contexts [2], its specific application in electrorefining relies on its ability to facilitate the transfer of copper ions. Impurities, known as anode mud, settle at the bottom of the cell during this process.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Activity 2.13 > p. 28
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 2: Acids, Bases and Salts > Activity 2.15 > p. 32