Colloids can be purified by

In soap lather,the dispersed phase and dispersion medium are respectively ....

Molar conductivity $\left(\Lambda_m\right)$ of an aqueous solution of sodium stearate,which behaves as a strong electrolyte,is recorded at varying concentrations $(c)$ of sodium stearate. Which one of the following plots provides the correct representation of micelle formation in the solution? (Critical micelle concentration $(CMC)$ is marked with an arrow in the figures.)

The size of a colloidal particle is

Give information about coagulation or precipitation.

On adding a few drops of dilute $HCl$ or $FeCl_3$ to freshly precipitated ferric hydroxide,a red-coloured colloidal solution is obtained. This phenomenon is called: