1. Chapter 2
2.2 – Properties of Water

2. 2.2 – Properties of Water Water (H2O) is a polar molecule
Polar – Unequal distribution of charge
Hydrogen side is slightly +
Oxygen side is slightly –
Hydrogen Bonding – the force
of attraction between a hydrogen
with a slightly + charge to another
atom with a slightly - charge
Water’s unequal charge allows it to
form hydrogen bonds and gives water its
unique properties

3. 2.2 – Properties of Water Properties of Water
Cohesion – attraction between like molecules
Hydrogen bonds between water molecules produces surface tension
Biological membranes
Adhesion – attraction between unlike molecules
Hydrogen bonds between water and other atoms allows water to dissolve many different substances
Water = the solvent of life
Adhesion and cohesion of water lead to capillary action
Heat Capacity – ability to resist a
change in temperature
Hydrogen bonding between water molecules
requires more energy than normal to cause a change in water temperature

4. Solvent Versatility as a Solvent for a variety of solutes
Due to water’s polarity, it is an excellent solvent
Water readily forms hydrogen bonds with ionic compounds
By doing so, water forms a hydration shell around these molecules causing them to dissolve in solution

5. 2.2 – Properties of Water Acids, Bases and pH
In some cases, certain substances dissolve in water and give off reactive ions
Acid – a substance, that when dissolved in water, gives off hydrogen ions (H+)
Base – a substance, that when dissolved in water, gives off hydroxide ions (OH-)

6. 2.2 – Properties of Water Acids, Bases and pH (cont.)
The strength of an acid or base depends on how much H+ or OH- is given off
Measured using the pH scale
pH 7 = neutral
pH from = acidic
pH from = basic (alkaline)
Buffer maintain homeostasis in organisms.
weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH.