Why are `Ag` and `Au` remain in anode mud during electrolysis refining of copper ?

Which of the following metal is thrown as anode mud during electrolytic refining of copper?

Name the common elements present as anode mud in the electrolytic refining of copper. Why are they so present?

During electrolysis the reaction occurs at anode is

In electro-refining of metal the impure metal is made the anode and a strip of pure metal the cathode during the electrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of:

An aqueous solution of copper sulphate, CuSO_(4) was electrolysed between platinum electrodes using a current of 0.1287 A for 50 min. [ Given atomic mass of Cu = 63. 5 g "mol"^(-1) ] ( i) Write the cathodic reaction. (ii ) Calculate (a) electric charge passed during electrolysis. (b) mass of copper deposited at the cathode. [ Given, 1 F = 96500 C " mol"^(-1) ]