At isoelectric point:

Which of the following is most effective in coagulating a ferric hydroxide sol?

Identify the correct statement regarding lyophilic colloids from the following.

The zig-zag motion (erratic motion) of particles in a colloid was observed by:

The conditions given below are in the context of observing Tyndall effect in colloidal solutions:
$A$. The diameter of the colloidal particles is comparable to the wavelength of light used.
$B$. The diameter of the colloidal particles is much smaller than the wavelength of light used.
$C$. The diameter of the colloidal particles is much larger than the wavelength of light used.
$D$. The refractive indices of the dispersed phase and the dispersion medium are comparable.
$E$. The dispersed phase has a very different refractive index from the dispersion medium.
Choose the most appropriate conditions from the options given below:

The macromolecular colloids among the following are:
$I$. Starch solution
$II$. Sulphur sol
$III$. Synthetic detergent
$IV$. Synthetic rubber