Question

Milk is an example of:
A. Suspension
B. True solution
C. Emulsion
D. None of the above

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 fats, proteins and sugar are suspended in water.

Complete answer:
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:
Oil in water emulsion: In these emulsions, oil is the dispersed phase and water is the continuous phase.
Water in oil emulsion: In these emulsions, water is the dispersed phase and oil is the continuous phase.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, milk is an emulsion of oil in water type.Thus, milk is an emulsion.

Thus, the correct option is C.

Note:A heterogeneous mixture in which solid particles are dispersed in liquid is known as a suspension. In suspension, the dispersed phase is solid and the dispersion medium is a liquid. A homogeneous mixture of two or more substances is known as the true solution. Particles of true solution cannot be isolated.