1. Why is water so important to life?

2. Extraordinary Properties of Water
Cohesion
Water molecules stick together
Surface tension
Adhesion
Water molecules cling to other solids
capillarity

3. Extraordinary Properties of Water
High Specific Heat
Amount of heat that must be absorbed for 1g to change 1o C for water = 1.00 cal/g/oC
Sp Heat of common liquids
Liquid SpHt (cal/g/oC)
Ammonia
Water
Eth alc
Acetone
Olive oil
Mercury

4. Extraordinary Properties of Water
High Heat of Vaporization
(change from liquid to gas)
Quantity of heat a liquid must absorb for 1g to be converted to the gas state for water = 576 cal/g
Ht of Vap of some liquids
Liquid Ht Vap (cal/g)
Water at 37C
Ammonia
Eth alcohol
Acetone
Mercury

5. Extraordinary Properties of Water
Water Expands when freezing
Ice Floats!
Water is most dense at 4oC, and expands just a bit to form ice crystals

6. Extraordinary Properties of Water
Water is a versatile solvent
Ionic compounds dissolve in water
Covalent compounds rich in O or N dissolve in water

7. Extraordinary Properties of Water
Adhesion and Cohesion
High Specific Heat
High Heat of Vaporization
Expands when freezing
Versatile Solvent

8. How does water do all this
How does water do all this? What allows water to facilitate life at the cellular and global level?

10. Hydrogen Bonds
A weak force of attraction between the H on one molecule and a highly electronegative atom on another molecule

11. Extraordinary Properties of Water
Versatile Solvent due to polarity
Adhesion and Cohesion---due to H bonds
High Specific Heat due to H bonds
High Heat of Vap due to H bonds
Expands when freezing ---due to H bonds

12. Ahh, water!