Saponification

Making Soap

“Soaponification”

Saponification Reaction:

Fat + Lye Soap + Glycerol

Lye - Caustic solution made from ashes.

Soda Lye = NaOH

Potash Lye = KOH

Combining potash K2CO3 with slaked lime Ca(OH)2 yields KOH and CaCO3

NaOH obtained from reacting sodium compounds.

O H

C17H35-C-O-C-H + NaOH

O

C17H35-C-O-C-H + NaOH

O

C17H35-C-O-C-H + NaOH

H

Fat Lye

(Triglyceride)

O H

C17H35-C-ONa H-C-OH

O

C17H35-C-ONa + H-C-OH

O

C17H35-C-ONa H-C-OH

H

Soap! Glycerol

How does it happen?? O

• Break the ester linkages C – O- by hydrolyzing the bonds between the carbon backbone and the fatty acid chains.

• (Reversal of esterification reaction)

• Form the sodium salt of a fatty acid (soap) and a trihydroxy alcohol (glycerol).

The Chemistryhttp://en.wikipedia.org/wiki/Saponification

• Organic Reaction: Slow!

• Must break covalent bonds.

• Refluxing: Technique which allows a volatile solvent to boil, condense and return to the reaction vessel. It helps to maintain a fairly constant temperature throughout the reaction period.

BUMPING!!!

• When superheated liquids above their boiling point suddenly boil.

• Large bubbles cause liquid to shoot out of container.

• Add boiling chips to prevent bumping.

Strange but true…

Fat in cadavers: saponifies if conditions are right. Alkalai environment, moist, minimal oxygen.

Adipocere or grave wax is formed.