Lyophilic sols are:

In electrophoresis,the colloidal particles of starch:

The coagulation values in millimoles per litre of the electrolytes used for the coagulation of $As_2S_3$ are given below:
$I$. $(NaCl) = 52,$
$II$. $(BaCl_2) = 0.69,$
$III$. $(MgSO_4) = 0.22$
The correct order of their coagulating power is:

The reason for the stability of a lyophobic sol is

Purification of colloids is done by the process of

What is the alum used for the purification of water?