1. Unit 2: Ecology
2.5 Properties of Water

2. Should we control a chemical that:
Causes excessive sweating and vomiting.
Is a major component in acid rain.
Can cause severe burns in its gaseous state.
Accidental inhalation can kill you.
Contributes to erosion.
Decreases the effectiveness of car brakes.
Has been found in tumors of terminal cancer patients.

3. What is the chemical?
Dihydrogen monoxide
Otherwise known as H2O

4. Question?
What molecule or compound is the most common In living Cells? Water - most cells are % water

5. The Water Planet

6. Properties Of Water Cohesive Adhesive High surface tension
Specific Heat- Can hold lots of heat
Expands when freezes
Versatile solvent

7. Liquid Water Is Cohesive
Cohesion: an attraction between molecules of the same substance
Water sticks to water due to the polarity of water resulting in hydrogen boding.

8. Liquid Water is Adhesive
Adhesion: an attraction between molecules of different substances.
Water sticks to other polar molecules due its hydrogen bonding

9. Water transport in trees uses Cohesion and Adhesion

10. Water Transport in Plants
Capillary Action: occurs when water sticks to the sides of a tube and creeps up, pulling other water molecules with them.
Imbibition: occurs when porous substances soak up water through capillary action.

11. Water Has A High Surface Tension
The surface of water is difficult to stretch or break.
Why? Hydrogen bonding!

12. Water Stabilizes Temperature
Water can absorb and store a huge amount of heat from the sun.
Result - climate moderation
Result - organisms are able to survive temperature changes.

13. Water Expands When It Freezes
The distance between water molecules increases from the liquid to the solid form.
Why? Hydrogen bonding
Result: aquatic life can live under the ice

15. Solids and Liquids
Water
Benzene
Sinks
Floats

16. Water Is A Versatile Solvent
Water will form a solution with many materials.
Why? Hydrogen bonding!

17. Solutions
SOLUTION: the mix of 2 or more different substance with one substance being liquid
SOLVENT: the substance in a solution present in greater amounts (liquid that does the dissolving).
SOLUTE: the substance in a solution present in lesser amounts (the substance that is being dissolved).

18. Hydrophilic Materials
Materials that dissolve in water.
Hydro - water
philic - to like or love
Have ionic or polar regions (polar covalent bonds) on their molecules for H+ bonds.

21. Hydrophobic Materials that repel water. Hydro - water phobic - to fear
Have non-polar covalent bonds. Ex - lipids.

22. Without Water Life Would Not Be Possible!!