Which of the following is lyophobic in nature?

Among the electrolytes $Na_2SO_4$,$CaCl_2$,$Al_2(SO_4)_3$,and $NH_4Cl$,the most effective coagulating agent for $Sb_2S_3$ sol is

The correct statement$(s)$ related to colloids is(are):
$(A)$ The process of precipitating colloidal sol by an electrolyte is called peptization.
$(B)$ Colloidal solution freezes at a higher temperature than the true solution at the same concentration.
$(C)$ Surfactants form micelles above the critical micelle concentration $(CMC)$. $CMC$ depends on temperature.
$(D)$ Micelles are macromolecular colloids.

Match the following:-

List-$I$	List-$II$
$A$. Dialysis	$IV$. Purification of colloidal mixture
$B$. Peptization	$I$. Precipitate converts to colloidal mixture
$C$. Flocculation	$II$. Precipitation of colloidal mixture
$D$. Gold number	$III$. Protective power

Purple of Cassius is:

If $1 \ mL$ of $10\% \ NaCl$ solution is added to $10 \ mL$ of gold sol containing $0.25 \ g$ of starch to prevent coagulation,what is the gold number of starch?