Question

what type of colloid is each of the following?

1. Milk
2. Fog
3. shaving cream

Short answer

1. Milk is emulsion type of colloid.
2. Fog is aerosol type of colloid.
3. Shaving cream is foam type of colloid.

Step-by-step solution

Colloid

a gelatinous or mucinous substance that is present in tissues during disease or naturally (as in the thyroid), a substance made up of particles that are too small to be resolved under a standard light microscope but too large to pass through a semipermeable membrane.

Type of colloid in milk

Milk is an emulsion of water and milk fat (liquid phase). An emulsion may be described as a colloid consisting of two or more non-homogenous liquid types, in which the dispersion of the various liquid forms is concentrated in one of the liquids.

Milk has tiny globs of butterfat suspended throughout the mixture. It is an example of liquid in liquid colloid commonly known as emulsion.

Category of colloid in fog

In a fog, the dispersed phase is a liquid, and the dispersion medium is a gas. Fog is classified as an aerosol if we want to categorise it as a type of colloid based on its physical condition.

Classification of colloid in shaving cream

A gaseous phase is spread inside a continuous liquid phase to create foam when shaving cream is applied.Shaving cream is consisting of tiny air bubbles dispersed in liquid. This type of colloid is called foam.