PolymersSAPONIFICATION

SAPONIFICATION

The making of soap from a fat or oil and a

caustic material such as lye or sodium

hydroxide

SOAP MOLECULESHAVE

BOTH

A POLAR

HEAD

&

A

NONPOLAR

TAIL

POLARITY OF SOAP MOLECULES

POLAR HEADS

– WATER- LOVING– HYDROPHILIC– COMPOSED OF

CHARGED OR PARTIALLY CHARGED PARTS

NONPOLAR TAILS

– WATER-FEARING– HYDROPHOBIC– COMPOSED OF A LONG

UNCHARGED HYDROCARBON CHAIN

“LIKES DISSOLVE LIKES”WATER

IS A

POLAR SOLVENT.

IT WILL DISSOLVE

POLAR SOLUTES

TO MAKE A

HOMOGENEOUS SOLUTION.

PARTIALLY NEGATIVE OXYGEN

PARTIALLY POSITIVE HYDROGENS

(polar molecules are called dipoles)

“LIKES DISSOLVE LIKES”HEXANE

IS A

NONPOLAR SOLVENT.

IT WILL DISSOLVE

NONPOLAR SOLUTES

TO MAKE A

HOMOGENEOUS SOLUTION.

UNCHARGED

HYDROCARBONCHAINS

NONPOLAR HEXANE

POLAR AND NONPOLAR ARE IMMISCIBLE

POLAR VINEGAR WILL NOT MIX

WITH

NONPOLAR OIL.

THE MIXTURE REMAINS

HETEROGENEOUS.

SURFACTANT ACTIONSOAP MOLECULES ARE SURFACTANTS, SURFACE SEEKING.

IN A BEAKER OF POLAR WATER, SOAP MOLECULES SEEK THE SURFACE.

Polar heads of soap molecules face toward polar water and nonpolar tails stick out.

water surface

SURFACTANT ACTIONSOAP MOLECULES ARE SURFACTANTS, SURFACE SEEKING.

IN A BEAKER OF NONPOLAR HEXANE, SOAP MOLECULES SEEK THE SURFACE.

Nonpolar tails of soap molecules face toward nonpolar hexane and polar heads stick out.

hexane surface

HOW DOES SOAP CLEAN?CONSIDER THE ENVIRONMENT:

AQUEOUS POLAR MEDIUM

NONPOLAR DIRT OR OIL

UNIQUE QUALITY OF SOAP MOLECULES

THE SOAP MOLECULES CAN SURROUND NONPOLAR DIRT OR

GREASE WITH THE POLAR HEADS POINTING OUT TOWARD THE

POLAR AQUEOUS MEDIUM AND THE NONPOLAR TAILS STICKING

INTO THE DIRT OR GREASE. THE RESULTING STRUCTURE IS

CALLED A MICELLE.

= GREASE OR DIRT

MICELLE FORMATION

This is a micelle. The interior green portion of the cluster is composed of hydrophobic nonpolar parts and the exterior is composed of hydrophilic polar parts.

CLEANING ACTION OF SOAPIn cleaning, the nonpolar ends

of soap molecules attach to nonpolar grease or dirt, letting

water seep in underneath.

The grease or dirt is pried loose and surrounded by soap

molecules with the polar ends facing out.

The micelles are then carried off by a flood of polar water.

Classzone has a 30 second clip of micelle formation.

micelle formation

SAPONIFICATION: THE CHEMICAL REACTION

`

OIL AND LYE SOAP AND GLYCEROL

THIS IS THE OVERALL REACTION!!!!!!

THE ASSESSMENT IS ON:• THE EQUIPMENT

AND PROCESSES USED IN THE LABORATORY

• HOW SOAP CLEANS CLOTHES, HAIR, SKIN AND DISHES

• THE STRUCTURE AND FUNCTION OF SOAP MOLECULES

• THE BOOK MATERIAL, PPT NOTES AND EDMODO VIDEOS

DISCUSSION QUESTIONS

• Soap was expected as the product in this reaction. Explain how the properties of the lab product are consistent with commercial soap.

• Describe the differences in the bubbles of the three soaps. Which soap bubbled the least and how would this be beneficial to its function?

• Describe the differences in the pH of the three soaps. Which soap had the pH farthest away from neutral (7)? Would you use this soap to wash your hair and face? Explain.

DISCUSSION QUESTIONS• Describe the results of adding calcium,

magnesium and iron ions to the soap solutions. The same phenomenon occurs when hard water and well water are used to wash hair, skin and clothes. In fact, the shower and tub also suffer. Explain.

• What are several reasons for error in this lab? Explain how each of these reasons impacts the results in this lab.