1. Water Properties Lab

2. Water is Polar Covalent

3. Hydrogen Bonds
Weak bonds between like molecules

4. Cohesion
Attraction of water to water

5. What forms a drop? Cohesion causes water to form drops
surface tension causes them to be nearly spherical
adhesion keeps the drops in place.

6. Surface Tension
Water attracts itself and pulls in to form a “film” on its surface to form a drop.

7. Adhesion Attraction of water to an unlike substance (like glass)
Note the drop is flatter than on wax paper

8. Water Drop Shapes
Water cohesion to itself and forms a nice, round drop.
Round drop on wax paper (not strong adhesion to water).
As adhesion to glass is stronger + pulls the water, it makes a flatter drop.

9. On wax paper On glass

10. Water on wax paper You can break surface tension with soap.
Plain wax paper Soapy wax paper
You can break surface tension with soap.

11. Polar coheres to Polar not Nonpolar
Water (Polar) has no adhesion to the wax (nonpolar) paper. It would roll right off.
Water has more adhesion to a glass plate.

12. Climbing Property of Water
Colors are separated by densities. Less dense colors go to the top.
Black is composed of all the colors.

13. Capillarity – water climbs up small spaces
The small spaces (pores of the paper) provide adhesion to the water.
The water makes a column by cohesion to itself.

14. Adhesion to paper Cohesion of water to water

15. Oil is hydrophobic Oil and water do not mix. Oil is on top
Water is on bottom

16. Food coloring dissolves in water.
Water is polar.
Food coloring is polar.
Oil is nonpolar (no charge).
Oil has no hydrogen bonding.
Polar molecules dissolve
polar molecules.

17. Stirring oil and water
The oil will go back to being separate from the water.

18. Oil sheen on water (oil on top of water in a thin layer)

19. Getting rid of oil on water
HowStuffWorks "How do you clean up an oil spill?“ (pick a video)
Detergent breaks up the oil into very small droplets.
Burn Off
Booms
Hi-pressure water

20. Slick Sack
Absorbent
pad
Hand washing

21. Oil Spills Problems
dead sea life
human life
cost of clean- up

22. Amphipathic
molecules have (hydrophobic) and to attract oil structure, but also have a region that is polar (hydrophilic) attracts water to wash it away.
Like detergent.