Should we control a
chemical that:
Causes
excessive sweating
and vomiting.
Is a major component in acid
rain.
Can cause severe burns in its
gaseous state.
Accidental
inhalation can kill
you.
Contributes to erosion.
Decreases the effectiveness
of car brakes.
Has been found in tumors of
terminal cancer patients.
What is the chemical?
Chapter 3
Water and the Fitness of
the Environment
Question?
What molecule Is the most
common In living Cells
The Water Planet
Properties Of Water
Be
ready and able to discuss
several of the following
properties.
Focus on definitions and
examples.
Review water structure and
H-bonds from Chapter 2.
Liquid Water Is
Cohesive
Liquid Water is
Adhesive
Water transport in trees uses
Cohesion and Adhesion
Water Has A High
Surface Tension
Water Has A High
Specific Heat
Heat
Temperature
Celsius Scale
Will
be used for most of our
temperature measurements.
Water Stabilizes
Temperature
Water Has A High Heat
Of Vaporization
Evaporative Cooling
Result:
Water Expands When
It Freezes
Solids and Liquids
Water
Benzene
Floats
Sinks
States of Matter
Solid
Liquid
Gas
Result
Aquatic
life can live under ice.
Water Is A Versatile
Solvent
Solution
Solvent
Solute
Hydrophilic Materials
Hydrophobic
Without Water
Life Would Not Be
Possible!!
Solution Concentration
Usually
based on Molarity.
Moles
One Mole of each
Sugar
Copper Sulfate
Sulfur
Mercury Oxide
Sodium Chloride
Copper
Comment
AP
Biology students should
be able to calculate solutions
in Molarity.
Dissociation of Water
Water
can sometimes split into
two ions.
In
pure water the concentration
of each ion is 10-7 M
Adding
certain solutes
disrupts the balance between
the two ions.
The two ions are very
reactive and can drastically
affect a cell.
Acids
Acid Rain
Acid Rain
Bases
Neutrals
pH Scale
pH Scale
Example:
For a neutral solution:
[H+] is 10-7
or - log 10-7
or - (-7)
or 7
Comment
[H+]
+ [OH-] = 14
Therefore, if you know the
concentration of one ion, you
can easily calculate the other.
Buffers
Summary
Be
able to discuss the
properties of water.
Be able to measure solution
concentrations in Molarity.
Be able to work pH scale
questions.