Question

In electrorefining of copper some gold is deposited at

• A. cathode
• B. anode mud
• C. cathode mud
• D. electrode

Answer 1

Answer: (B)

anode mud

Answer 2

In electrolytic refining of copper some gold is deposited below anode. Impure copper usually contains $Ag,\, Au,\, Ni,\, Zn,\, Fe,\, Pb,\, Sn$ etc, as impurity. Impure metal is taken as anode dipped in the acidified solution of copper sulphate. The impurities of $Ni$, Fe and $Zn$ pass into solution as sulphate while impurity of $Ag,\, Au$ and $Sn$ etc. Are thrown down as anode mud below anode.