1. Unique Water Properties
Energy and Matter
Unique Water Properties

2. Water and Solutions
In comparison to a jellyfish, our bodies are both made up of cells composed mostly of water.
Chemical reactions occurs in aqueous solutions

3. Polarity Water molecule Hydrogen shares electrons with oxygen
Hydrogen bonds are formed at an angle
Negative charge on oxygen and positive charges on Hydrogen create a polar compound

4. Solubility of Water Polar can dissolve other polar substances
Dissolved substances are found in all living things
Essential to maintain normal body functions
Muscle contractions
Nerve impulses

5. Hydrogen Bonding
Hydrogen bonds allow water molecules to “cling” to each other & other substances
Provide the unique properties of water
Adhesion
Cohesion
Temperature Moderation
Density of ice
Polarity

6. Cohesion
Water molecules stick to each other
Surface tension

7. Adhesion Attraction to different substances Glass molecules and water
Capillary action

8. Temperature Moderation
Absorb or release large amounts of energy with just a slight change in its own temperature
Specific heat
Hydrogen bonds
Water can absorb large amount of energy from sun during the day and slowly release it at night
Oceans stabilize Earth’s temperature
Organism’s can keep cells at even temperature despite changes in the environment

9. Temperature Moderation
Evaporative cooling
Liquid evaporates taking heat with it
Remaining liquid is cool
Prevents overheating of land organisms

10. Density of Ice Solid water is less dense than liquid
Shape of water molecule & hydrogen bonding
Angle between hydrogen atoms so wide that open spaces are formed as it becomes solid
Ice floats
Ponds and lakes freeze top down
Important for aquatic organisms

11. Acids and Bases Ionization of water Water molecules move
Collisions occur & some strong enough to knock off a Hydrogen atom
The loose Hydrogen then joins another water molecule
H2O <-> H+ + OH- (Hydroxide ion)
H+ + H2O <-> H3O + (Hydronium ion)
If hydronium ions are greater solution is acidic

12. pH scale (0 acidic, 7 neutral, 14 basic) Buffers
H3O + (Hydronium ion)
Sour taste and highly corrosive
Basic or Alkaline
OH- (Hydroxide ion)
Bitter taste and slippery
pH scale (0 acidic, 7 neutral, 14 basic)
Buffers
Chemical substances used to neutralize small amounts of either an acid or base