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

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

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

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

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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

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

                                                            

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

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

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

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

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

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