Sulphur sol contains:
A.Discrete Sulphur atoms
B.Discrete Sulphur molecules
C.Water dispersed in solid Sulphur
D.Large aggregates of Sulphur molecules

Hint: To answer this question, you must recall the various types of colloids possible. Colloids are a type of mixtures in which the particle size is bigger than that in a true solution but smaller than that in a suspension. The solute remains dispersed in the solvent and does not settle down as precipitate. Sols are also a type of colloid.

Complete step by step answer:
- A sol of Sulphur is an example of a multimolecular colloid. A Sulphur sol contains particles of various sizes composed of about a thousand molecules of Sulphur.
- A multimolecular colloid is a type of colloid in which a large number of atoms or small sized molecules of a substance combine with each other in the dispersion medium forming aggregates whose sizes lie in the colloidal range.
- Thus, we can say that Sulphur sol contains large aggregates of Sulphur molecules.

Thus, the correct answer is D.

Note:
- Colloidal solutions are classified as multimolecular colloids on the basis of the properties of the sol particles. This classification is different from the one based on the interaction forces between the dispersed phase and the dispersion medium, i.e., lyophobic and lyophilic sols.
- Apart from multimolecular colloids, the other types of colloids under the same classification are macromolecular colloids. In these colloids, the substances form large molecules whose dimensions are similar to those of colloidal particles. These molecules have very large molecular masses and are thus known as macromolecules.
- When mixed in a suitable dispersion medium, these substances result in the formation of macromolecular colloids. They are different from multi molecular colloids as the particles are already large in size while in the latter, small particles aggregate to form large particles.