When an alloy of silver and lead is rich in silver,which process is used for purification?

In the extraction of nickel by the Mond process,the metal is obtained by:

One of the following metals forms a volatile compound and this property is taken advantage of for its extraction. This metal is

The method used for producing semiconductor grade metals of high purity is

Which of the following statements are correct related to metallurgy?
$A$. In electrolytic refining of copper,pure $Cu$ is used as anode.
$B$. Zone refining is based on the principle that impurities are more soluble in the melt than in the solid state of the metal.
$C$. $TiI_4$ upon heating will give pure $Ti$.
$D$. Very pure $Zr$ may be obtained by galvanisation.
$E$. In copper smelting,hot air is used to convert to $CuSO_4$.
The correct answer is

Silver can be separated from lead by