honors biology - water

WATER

WATER AND THE FITNESS OF THE ENVIRONMENT

OUTLINE

Polar Molecule and Hydrogen Bonds

Properties of Water

Acid and Base

H BONDS

FORMATION OF HYDROGEN BONDS

ALL ABOUT WATER

1. COHESIVE BEHAVIOR

Surface Tension

2. MODERATION OF TEMPERATURE

HIGH SPECIFIC HEAT

Water = 1 cal/g/ºC

Related to bonding:

• Heat is absorbed when hydrogen bonds break

• Heat is released when hydrogen bonds form

High specific heat of water minimizes temperature fluctuations.

HIGH HEAT OF VAPORIZATION

Heat a liquid must absorb for 1 g to be converted to gas.

Evaporative cooling.

3. EXPANSION WHEN FROZEN

ICE FLOATS

4. SOLVENT OF LIFE

Terms you should know!

•Solution•Solvent•Solute

Water dissolves ionic…

…and nonionic polar compounds.

HYDROPHOBIC

Scared

HYDROPHILIC

Loving

ACIDS AND BASES

POSSIBLE SHIFTS

Changes in concentrations can drastically affect the chemistry of a cell

(H+ Ions - Hydrogen)

ACID

A substance that increases the H+ concentration of a solution.

pH values less than 7

[H+] > [OH-]

BASE

A substance that reduces the H+ concentration of a solution.

pH values greater than 7

[H+] < [OH-]

BUFFERS

Minimize changes in concentrations of H+ and OH- in a solution.

IN THE ENVIRONMENT