The Chemistry of Life
Properties of Water
Neutral Charge – ZERO
Have no charge
Have an Equal number of p+ and e-
Charges aren’t evenly distributed
The Water Molecule
A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms.
Polar water molecules act like magnets and attract each other
The attraction of the Hydrogen end (+) of one molecule for the Oxygen end (-) of another water molecule.
They are strong bonds that form between molecules (CO2, H2O, …)
The attraction between molecules of the same substance (e.g. water).
H2O attracting other H2O molecules
Allows some insects and spiders to walk on water.
Adhesion - Attraction between H2O molecules and different molecules
Cohesion & adhesion produce Capillarity (upward movement against gravity of water through small tubes)
Question: How do plants make use of Capillarity?
Water is usually part of a mixture.
Because so many things dissolve in water, it is called the Universal Solvent
There are two types of mixtures:
Ionic compounds disperse as ions in water (+ions & -ions spread out among polar water molecules)
Solutions are Evenly distributed mixtures
Substance that is being dissolved
Dissolving Substance for the solute
Na+ ions will be attracted to WHAT END of the water molecule?
Substances that don’t dissolve but separate into tiny pieces.
Water keeps the pieces suspended so they don’t settle out.