Concentration

1
A physicist, a biologist and a chemist go to the
ocean for the first time. . . . . . . . The
physicist is fascinated by the waves. He says he
wants to research the fluid dynamics of the waves
and walks into the ocean never to return (he
drowns). . . . The biologist says he wants to
research the organisms in the ocean and he too
walks in, never to return (he drowns too). . . .
The chemist waits for a long time and
afterwards, writes the following
observation Physicists and biologists are
soluble in ocean water.
2
Chapter 16.1-16.3
SOLUTIONS
3
What is a solution?
A homogeneous mixture that cannot be separated by
filtration.
4

• A solvent dissolves the solute.
• Solvents and solutes may be gases, liquids, or
  solids.
• The solute becomes dispersed in the solvent.
• Solute particles can be atoms, ions, or
  molecules.

5
Solvation the process of surrounding solute
particles with solvent particles
6
Things that increase rate of solvation
(dissolving)
1. Stirring
2. Temperature
3. Particle size
7
Like Dissolves Like
Polar solvents such as water dissolve ionic
compounds and polar compounds.
8
Which one dissolves in water?
The
POLAR
bear!
9
Like Dissolves Like
Nonpolar solvents such as oil dissolve other
nonpolar compounds.
10
Miscible (soluble) substances will dissolve in
each other.
11
Immiscible (insoluble) substances will not
dissolve in each other.
12
SOLUBILITY

• The amount of substance that dissolves in a given
  amount of solvent at a specified temperature and
  pressure.
• Temperature
• Pressure

(Unless its a gas in liquid)
13
Concentration
The amount of solute in a solution.
ppb

• Percent by mass
• Percent by volume
• Molarity
• Molality
• Mole fraction

ppm
mg/L
14
Percent by mass
mass of solute X 100 mass solution
15
Percent by volume
volume of solute X 100 volume solution
16
Molarity (M)
moles of solute Liter of solution
17
ug of solute Liter of solution
ppm
ppb
mg of solute Liter of solution
18
Molality (m)
moles of solute kg of solution
19
Mole fraction
3 star-nosed moles 9 star-nosed Eastern moles
moles of solute moles of solute moles of solvent
20
Colligative Properties(Physical properties of
solutions that are affected by numbers of
particles, not identity of particles)

• Vapor pressure lowering
• Boiling point increase
• Freezing point lowering

21

• Vapor pressure lowering