Download pH, Buffers, and Water Notes

pH, Buffers, and
Water Notes
General Biology
pH, water notes outline
Acids, bases
Properties
1. pH scale
1. high surface ten.
2. acids
2. capillary action
3. bases
3. high heat of vap.
4. neutral
4. resists temp
II. Stable environment
5. expands when
freezes
III. Water
universal solvent
transport vessel
I.
pH….
• Measure of how acidic or basic a solution is
• Scale ranges from 0-14
 Acid: forms H+ ions in water, pH
<7
examples: lemon juice, vinegar
 Base: forms OH- ions in water,
pH > 7
examples: blood, ammonia
 Neutral: pH = 7

Organisms need stable
environments to survive and
perform chemical reactions so….
 BUFFERS
help to maintain steady
pH (homeostasis) by adding or
taking H+ ions as needed to
neutralize a solution
Water (h2o)
• Water takes up 70-95 % of most
organisms
• Most important compound in living
organisms, acts as a universal solvent
and transport vessel
Water
• Covers ¾ of the earth, most
common liquid
• Polar molecule because O and H
share electrons unequally
5 properties of water that
make life on earth possible:

1. High Surface Tension
– Water molecules stick together
(cohesion)

2. Capillary Action
– Water molecules are attracted to other
molecules (adhesion) and can creep up
thin tubes; allows for movement and
transport
•3. High Heat of Vaporization
– Lots of energy required to
evaporate; helps cool body by
removing heat when sweating
4. Resists Temperature Change
– Keeps organisms’ environment
stable
 5.
Expands when freezes
 Causes ice to float,
forms soil by cracking
rocks