1. Polarity of Solvents

2. A Hydrocarbon Typical petroleum product Non-polar C18H38 CH2 CH2 CH2

3. Oil and Water Don’t Mix Oil is nonpolar Water is polar
“Like dissolves like”
Lycopodium Powder demonstration.
Lycopodium powder is a nonpolar hydrocarbon that doesn’t mix with water. It is dry to the touch and not oily feeling. Sprinkle lycopodium powder on top of a beaker of water. Slowly, push your finger through the surface of the lycopodium powder into the water. Slowly withdraw your finger, it remains dry the entire time. Why?
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 470

4. Hydrogenation + H2 shortening stick margarine tub (soft) margarine
vegetable oils
+ H2
FOOD SUBSTITUTES
“Chemistry is widely used in the food industry to manufacture new convenient foodstuffs and to check for impurities. Butter is known as a saturated fat, whereas most vegetable oils, which are normally liquid, are polyunsaturated fats. They can be changed to solids, such as margarine, by a chemical process called hydrogenation – the addition of hydrogen to the oils using a catalyst. Hydrogenation makes the oil more like butter and easier to spread. Margarine was first developed in the 1860’s in France as a cheap butter substitute.”
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 7
heat, nickel
catalyst
Timberlake, Chemistry 7th Edition, page 570

5. Molecular Polarity H nonpolar molecules: -- e– are shared equally
H–C–H H
nonpolar molecules: -- e– are shared equally
-- tend to be symmetric
e.g., fats and oils H O
polar molecules: -- e– NOT shared equally
e.g., water
“Like dissolves like.”
polar + polar = solution
nonpolar + nonpolar = solution
polar + nonpolar = suspension (won’t mix evenly)

6. Using Solubility Principles
Chemicals used by body obey solubility principles.
-- water-soluble vitamins: e.g., vit. C
-- fat-soluble vitamins: e.g., vits. A, D
Dry cleaning employs nonpolar liquids.
-- polar liquids damage wool, silk
-- also, dry clean for stubborn stains (ink, rust, grease)
-- (tetra) perchloroethylene is in common use
C=C Cl

7. One unit washes and dries
Dry Cleaning Unit-
One unit washes and dries
Washing Process
Drying Process
Process used for
Wash and dry
Pressing
Dirty
Clothes
Air to
Atmosphere
Warm Vapor
From Dryer
Dirty
Perc
Filter
Condenser
Perc
Used,
Filtered
Perc
Separator
New
Perchloro-
ethylene
(PERC)
Condensed
Liquid Perc
Finished
Clothes
Perc Storage/
Collection
Clean
Perc
Collected
Used
Perc
Water Discharge
Hazardous
Waste*
Distiller
*Soil, dirt, unrecovered Perc

8. MODEL OF A SOAP MOLECULE
emulsifying agent (emulsifier):
-- molecules w/both a polar AND a nonpolar end
-- allows polar and nonpolar substances to mix
e.g., soap
detergent
lecithin
eggs
MODEL OF A SOAP MOLECULE
Na1+
NONPOLAR
HYDROCARBON
TAIL
POLAR
HEAD