Soap molecules have a hydrophilic head and a hydrophobic tai

Soap molecules have a hydrophilic head and a hydrophobic tail. What happens when you put soap in water?

The hydrophobic tails cluster together and exclude water

The hydrophilic heads interact with water

The hydrophobic tails bind to one another

Only A and B are true

A, B, and C are all true

Solution

Soap molecules are amphipathic in nature, i.e. they have both polar and non-polar constituents in them. The polar head, composed of a salt group, is joined to a hydrophobic tail, which is non-polar. When the soap molecules are placed in water, these molecules orient themselves such that the polar head group interacts with water, whereas the hydrophobic chains bind to one another, so as to minimize the contact with water. The hydrophobic chains form a cluster, and this structure is known as micelles.

Thus, option (E) is correct, because statements A, B, and C are all true.