What is the chemical structure of soap.

Soaps consist of molecules one end of which is hydrophilic
or is attracted to water. The other end is hydrophobic or is repelled by water and
instead is attracted to oil. We cannot clean oil with plain water as oil is not soluble
in water. The soap forms a link between the oil droplets and water and allows oil to be
cleaned.

Soaps are created as soluble salts of sodium
potassium and carboxylic acids. The most widely used salt is a sodium stearate.  This
has the property that it dissolves in water and forms ions of sodium and stearate.  The
stearate ion is mostly made of hydrocarbon but it dissolves in water due to a
carboxylate group it has.  The carboxylate end is the called hydrophilic end, and the
hydrocarbon tail is the hydrophobic end.