Question

Milk is
A) Gel
B) Protein
C) Emulsion
D) Fat

Answer 1

Hint:We know that milk contains fats, proteins, lactose which is a sugar and water. The proteins that are present in milk are casein proteins. In milk, the casein proteins form micelle which are tiny spheres.

Complete answer
We know that milk contains fats, proteins, lactose which is a sugar and water. The proteins that are present in milk are casein proteins. In milk, the fats, proteins and sugar are suspended in water.

A colloidal solution in which liquid particles are dispersed in a liquid medium is known as emulsion. Thus, in an emulsion, dispersed particles and the dispersion medium both are in liquid phase.

Milk is an emulsion in which fat globules are suspended in water. Casein is a lyophilic (solvent loving) sol. Casein stabilizes the milk emulsion and thus, casein acts as an emulsifier for milk.Milk is an oil in water type of emulsion because fat globules in milk are suspended in water.Thus, in milk, flat globules are dispersed in water.Thus, milk is an emulsion.

Thus, the correct answer is option (C) emulsion.

Note:A fine dispersion of minute droplets of one liquid into another liquid in which it is not soluble is known as an emulsion.
Emulsions are of two types:
i) Oil in water emulsion: In these emulsions, oil is the dispersed phase and water is the continuous phase.
ii) Water in oil emulsion: In these emulsions, water is the dispersed phase and oil is the continuous phase. The examples of emulsion are: paints, smoke, etc.