Sol is a type of colloid in which solid particles are dispersed in a liquid medium.
The type of sol in which a large number of small molecules (having diameters of less than ) of a substance combine together in a dispersion medium to form aggregates is known as a multimolecular sol.
Gold sol is a negatively charged sol having diameters of particles less than .
Hence, gold sol is an example of multimolecular sol.