'Softening of lead' means

Which method of purification is represented by the equation
$Ti + 2I_2$ (Impure) $\xrightarrow{500 \ K} TiI_4$ $\xrightarrow{1675 \ K} Ti + 2I_2$ (Pure)

Which one of the following methods can be used to obtain highly pure metal which is liquid at room temperature?

In the electrolytic purification of copper,some gold is found in the:

In electrorefining of metals,the anode and cathode are taken as a thick slab of impure metal and a strip of pure metal,respectively,while the electrolyte is a solution of a complex metal salt. This method cannot be applied for the refining of:

The metal purified by Mond process is $\underline{X}$ and metal purified by van Arkel method is $\underline{Y}$. $X$ and $Y$ respectively are