Question

Difference between suspension and colloid.

Answer 1

A colloid is a substance in which microscopic particles are dispersed in a medium, but are not dissolved in it. If left undisturbed, the dispersed particles will not settle or form sediment. Pumice could be an example of a colloid: particles of air dispersed in solid stone.

An emulsion is a particular type of colloid, referring to microscopic particles of liquid dispersed in another liquid. Milk could be an example of an emulsion: lipophilic butterfat particles dispersed in a water-based medium.

A suspension is similar to a colloid except that the dispersed particles tend to be larger and will eventually settle or form sediment. Sand in water could be an example of a suspension: if shaken then the sand will disperse in the water, but if left alone it will settle at the bottom.