question_answer 24)

 What are emulsions? What are their different types? Give example of each type.

Answer:

Emulsions are the colloidal solutions of two immiscible liquids in which dispersed phase as well as the dispersion medium are liquids. Since the two do not mix well, the emulsion is generally unstable and is stabilised by adding a suitable reagent called emulsifier or emulsifying agent. e.g., gum, soap, glass powder, etc. Type of Emulsions. These are of two types: (i) Oil-in-water emulsions. In this case, oil acts as the dispersed phase while water is the dispersion medium. For example, milk is an emulsion of fats in water and here casein acts as an emulsifier. Such emulsions are called aqueous emulsions. (ii) Water-in-oil emulsions. In this case, water acts as the dispersed phase while the oil acts as the dispersion medium. For example, butter, cod liver oil, cold cream etc. Such types of emulsions are called oily emulsions.