In the electrolytic refining of a metal, what are the insoluble impurities that settle down at the bottom, below the anode, called?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Anode mud
In electrolytic refining the impure metal is the anode and a thin strip of pure metal is the cathode. The pure metal dissolves from the anode and deposits on the cathode, while the insoluble impurities settle down below the anode as anode mud.