1. Water & Life
Chapter 3

2. H2O is why we are here H2O molecules are polar
What does their polarity contribute to?
Each H2O molecule can form __ Hydrogen bonds?

4. Cohesion & Adhesion Caused by Hydrogen bonding
Cohesion – Water-to-water
Adhesion – Water-to-something other than water
When water travels upward in a straw, is that cohesion or adhesion? Why?
Diameter of straw: small or large? Why?

5. Transpiration (Plants)

6. Structure & Function in Water Transport
What structural feature of water enables it to be transported upward?
What structural feature of plant vessels enables water to be transported upward?

7. Properties of Water 1. High Surface Tension 2. Temperature Moderation
3. Evaporative Cooling
4. Significant Solvency

8. Surface Tension
Surface Tension – water can stand above the rim of a glass due to hydrogen bonds
Is surface tension a result of cohesion or adhesion?
Why?

9. Temperature Moderation
Temperature – measure of average kinetic energy of molecules -- Water does this because it has a high specific heat  Water can absorb large amounts of heat but change little in temperature  Guess what type of bonding is responsible for high specific

10. Sea Breeze? (cranberry juice & …)
Day, land heats up faster (low specific heat)
Air over land rises
Onshore breeze
Night, lands cools faster
Hot air rises over water
Offshore breeze

11. Evaporative Cooling Water has high specific heat due to?
Responsible for cooling
Heat is released as liquid is vaporized into gas
Highest energy molecules are vaporized first
Vaporization involves the breaking of which bonds?

12. Hydrogen Bonding is cool

13. Water Which is more dense, liquid or solid H2O?
As temperature increases, what happens to density?
Why?
What does this mean for ocean stratification?
Which temperature (Celsius) is H2O the most dense?

14. Properties of Water
1. There are two cities, Davie and Pompano Beach, which will have a higher temperature during summer?
Why can we not use Weston instead of Davie?
2. What bonds are broken during evaporative cooling?
3. What force is responsible for cohesion?
4. What force is responsible for adhesion?

15. Like dissolves like… Water is polar so it dissolves polar substances
Also dissolves ionic solids (salts)
Polar substances = hydrophilic
Hydro = water -philic = to like
(Dendrophiliac – one who likes trees)
Water does not dissolve nonpolar substances
Nonpolar substances = hydrophobic
Hydro = water -phobe = to fear
(Triskaidekaphobe – one who fears the number 13)

16. Remember… Hydrophilic = polar molecule Hydrophobic = nonpolar molecule
Will dissolve in water
Hydrophobic = nonpolar molecule
Will NOT dissolve in water
What about ionic compounds?