Which refining process is represented by the equation $Ti_{(s)} + 2I_{2(g)}$ $\xrightarrow{523 \ K} TiI_{4(g)}$ $\xrightarrow{1700 \ K} Ti_{(s)} + 2I_{2(g)}$?

In the electrolytic refining of an impure metal,a rod of impure metal is used as the anode and a rod of pure metal is used as the cathode,and the aqueous solution of its salt is electrolyzed. Which of the following metals cannot be refined by this method?

Impurities of lead in silver are removed by

Which of the following is the correct match?

Hoop's process is used for the purification of the metal:

In the electrolytic refining of metals,the electrolysis of an aqueous solution of its complex salt is performed using an impure metal as the anode and a strip of pure metal as the cathode. This method cannot be used for the refining of which of the following metals?