Question

Which of the following is/are correctly matched? (This question has multiple correct answers).
(a)- Butter-gel
(b)- Milk-emulsion
(c)- Fog-aerosol
(d)- Dust-solid sol

Answer 1

Hint: The colloids have two components, one dispersion phase which is less in quantity, and a dispersion medium which more in quantity. In solid-sol both the dispersion phase and medium are solid.

Complete answer:
Colloidal state of matter is, therefore, a state in which the size of the particles is such (1 to 1000 nm) that they can pass through filter paper but not through animal or vegetable membrane.
Just as in true solution, the substance dissolved is called the solute, and the medium in which it is dissolved is called the solvent, similarly, in a colloidal system, the terms solute and solvent are replaced by the terms dispersed phase and dispersion medium respectively. Thus, dispersed phase means the substance distributed in the dispersion medium in the form of colloidal particles and the dispersion medium is the medium in which the substance is dispersed in the form of colloidal particles, the colloidal system thus obtained is sometimes called colloidal dispersion or simply colloid.
Let us study the options one by one:
(a)- Butter-gel
The gel is the colloid in which the dispersion phase is liquid and the dispersion medium is solid. Butter is an example of a gel.
This option is correct.
(b)- Milk-emulsion
The emulsion is the colloid in which the dispersion phase is liquid and the dispersion medium is liquid. Milk is an example of an emulsion.
This option is correct.
(c)- Fog-aerosol
The aerosol is the colloid in which the dispersion phase is liquid/solid and the dispersion medium is gas. Fog is an example of aerosol.
This option is correct.
(d)- Dust-solid sol
Solid sol is the colloid in which the dispersion phase is solid and the dispersion medium is solid. Dust is an example of aerosol.
This option is incorrect.

Hence, (a), (b), and (c) are correct.

Note:
Foam is the colloid in which the dispersion phase is gas and the dispersion medium is gas, for example, froth, whipped cream. Solid foam is the colloid in which the dispersion phase is gas and the dispersion medium is solid. There is no colloid in which the dispersion phase and medium both are gas.