Colloidal solutions can be purified by

When a freshly precipitated substance is converted into a colloidal solution with the help of a third substance,the process is known as

Which of the following substances gives a positively charged sol?

Which one of the following is most effective in causing the coagulation of an $As_2S_3$ sol?

The density of gold is $19 \ g/cm^3$. If $1.9 \times 10^{-4} \ g$ of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius $10 \ nm$,then the number of gold particles per $mm^3$ of the sol will be

The colloidal system consisting of a liquid dispersed phase in a solid dispersion medium is termed as: