1. 2.2: Properties of Water
water is one of the most important substances on Earth and in your body
70% of your body IS water

2. The Water Molecule has an equal number of P(+) and e(-)
neutral = no charge
BUT! the charges aren’t evenly distributed 2

3. one end seems negative while the other is positive – called a polar molecule
(-)
(+) 3

4. polar water molecules act like magnets and attract each other
attraction between the HYDROGEN end (+) of one water molecule to the OXYGEN end (-) of another water molecule forming hydrogen bonds 4

5. 5

6. solutions & suspensions
water is usually part of a mixture – 2 or more substances physically mixed together
can be separated easily
~ salt and pepper mixed
there are two types of mixtures:
solutions & suspensions 6

7. Properties of Solutions
solutions are evenly distributed mixtures
solute: substance that is being dissolved (usually a solid)
solvent: dissolving substance for the solute (liquid) 7

9. suspensions are mixtures where really small particles stay suspended in the water but do NOT dissolve in it
blood is a great example – it is mostly water with small cellular parts (red & white blood cells, platelets, plasma)
red blood cells
platelets

10. in any given sample, a small number of water molecules will have their bonds break
H2O  H+ + OH-
this forms a hydrogen ion (H+) and a hydroxide ion (OH-)
pure water contains the same amount of both ions

11. The pH Scale indicates the concentration of H+ ions ranges from 0 – 14
pH of 7 is neutral (pure water) 11

12. How much stronger is a pH 3 than a pH of 5?
pH 0 up to 7  acid (H+)
pH above 7 to 14  base (OH-)
each pH unit represents a factor of 10X change in concentration
How much stronger is a pH 3 than a pH of 5?
100 times

13. lower number of OH- ions
Acids
high in H+ ions
lower number of OH- ions
0 – 3 are strong acids 13

14. Bases high in OH- ions lower number of H+ ions
11 – 14 are strong bases 14