The charge on colloidal particles can be determined by $......$.

Match the following types of colloids with their examples:

Column-$I$	Column-$II$
$A$. Liquid Aerosol	$P$. Milk
$B$. Solid Sol	$Q$. Fog
$C$. Emulsion	$R$. Gel
$D$. Jelly	$S$. Alloy

Under identical conditions,which of the following surfactants will form micelles at its lowest concentration?

Gold numbers of protective colloids $A, B, C$ and $D$ are $0.50, 0.01, 0.10$ and $0.005$,respectively. The correct order of their protective powers is

Assertion : $Fe^{3+}$ can be used for coagulation of $As_2S_3$ sol.
Reason : $Fe^{3+}$ reacts with $As_2S_3$ to give $Fe_2S_3$.

The coagulation of $200 \ mL$ of a positive colloid took place when $0.73 \ g$ of $HCl$ was added to it without changing the volume much. The flocculation value of $HCl$ for the colloid is