Properties of Water

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Slide 1

The Chemistry of Life

Properties of Water

Slide 2

The Water Molecule

Neutral Charge – ZERO

Have no charge

Have an Equal number of p+ and e-

Charges aren’t evenly distributed

Slide 3

The Water Molecule

Polarity

A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms.

(-)

(+)

Slide 4

Hydrogen Bonds

Polar water molecules act like magnets and attract each other

Hydrogen Bonds

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, …)

Slide 5

Hydrogen Bonds

Slide 6

Cohesion

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.

Slide 7

Adhesion & Capillarity

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?

Slide 8

Solutions & Suspensions

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:

Solutions

Suspensions

Slide 9

Properties of Solutions

Ionic compounds disperse as ions in water (+ions & -ions spread out among polar water molecules)

Solutions are Evenly distributed mixtures

SOLUTE

Substance that is being dissolved

SOLVENT

Dissolving Substance for the solute

Slide 10

Ionic Solutions

Na+ ions will be attracted to WHAT END of the water molecule?

Slide 11

Suspensions

Substances that don’t dissolve but separate into tiny pieces.

Water keeps the pieces suspended so they don’t settle out.