polymers saponification. the making of soap from a fat or oil and a caustic material such as lye or...
TRANSCRIPT
SAPONIFICATION
The making of soap from a fat or oil and a
caustic material such as lye or sodium
hydroxide
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
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
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.