The non-
polar hydrocarbon end of the soap molecule is repelled by water. Here
is a diagram of the monolayer of soap, which is made by a drop or two
of soap in water, when the soap molecules "stand up"(because
the non polar hydrocarbon tails are repelled by water), on the surface
as the polar carboxyl salt end is attracted to the polar water. 
Figure 5: Monolayer of Soap on Water
Vocabulary List
Saponification:
The process of soap making
Basic hydrolysis reaction: The process of soap making
Brine: leftover of saponification
Salt: the result of an acid and an alkali reacting together.
Lye: sodium hydroxide
Potash: potassium hydroxide
triglyceride molecule: they are made up of three fatty acid molecules
that are attached to one molecule of glycerine. There are many types of
triglycerides that each consists of it’s own particular combination
of fatty acids.
fatty acids: long chain of hydrogen and carbon that contains an
extra hydrogen atom at one end and a carboxyl group at the other, which
is basically made up of two oxygen and one hydrogen and carbon atom.
Alkali: The base, either sodium hydroxide or potassium hydroxide,
depending on which is used.
Hard Soap: produced by long-chain fatty acids that don’t mix
well with water
Soft Soap: produced by shorter hydrocarbon chains into semi- solid
and liquid soaps.
Glycerin: A byproduct of making soap out of natural ingredients
when fats or oils are reacted with alkali.