Which one of the following is used as a disinfectant in water treatment?

Which of the following substances forms a positively charged sol?

The density of gold is $19 \, g/cm^3$. If $1.9 \times 10^{-4} \, g$ of gold is dispersed in $1 \, L$ of water to form a sol of spherical gold particles of radius $10 \, nm$,find the number of gold particles per $nm^3$ in the sol.

Which of the following is a lyophobic colloidal solution?

Which of the following is a lyophobic colloidal solution?

Which of the following molecules is most suitable to disperse benzene in water?