Solutions
Solubility - Henry’s Law
Section 15.1
Solvation Review
1.
2.
3.
4.
Explain the difference between a
homogeneous and a heterogeneous mixture.
Give an example of a solute and an example
of a solvent.
What states of matter can solutions consist of?
Explain the difference between soluble and
insoluble. Give an example of a substance
soluble in water and a substance insoluble in
water.
Solvation Review
5.
6.
7.
8.
Explain the terms miscible and
immiscible and give an example of each.
What is the difference between a soluble
substance and a miscible substance?
Describe the Tyndall Effect and the type
of mixture it affects.
What are the three factors that affect the
rate of solvation?
Temperature and Solubility
 As
temperature is increased the solubility
of a solid solute will generally increase,
with a few exceptions:
• As the temperature is increased, the solubility of a
gas will decrease. At higher temperatures the gas
molecules move much faster than they do a lower
temperatures. So as a general rule gases are less
soluble in hot liquids than in cool liquids.
That is why in the summer time there are a lot of fish
kills in some estuaries due to the water being warmer
and less oxygen available for the fish.
Pressure and Solubility – Henry’s
Law
 Henry’s
Law – The solubility of any
gas increases as the external
pressure is increased
 This equation describe Henry’s Law:
S1 = S2 ‘s’ = solubility
P1 P2 ‘p’ = pressure
Pressure and Solubility – Henry’s
Law

Example: carbonated beverages – once you
“pop the top” on a Coke, the external pressure
has been reduced, and the solubility of the
CO2 goes down. This is why Coke goes “flat”
in a very short amount of time.
Henry’s Law Practice Problems I
S1/P1 = S2/P2
1. If 0.55 g of a gas dissolves in 1.0 L of water at 2 atm of
pressure, how much will dissolve at 4.5 atm of pressure?
2. A gas has a solubility of 0.66 g/L at 10 atm of pressure. What is
the pressure on a 1.0 L sample that contains 1.5 g of gas?
Henry’s Law Practice Problems I
S1/P1 = S2/P2
3. If .68 g of a gas at 5 atm of pressure dissolves in 1.0 L of
water at 25oC, how much will dissolve in 1.0 L of water at 8
atm of pressure and the same temperature?
4. A gas has a solubility of 1.46 g/L at 8 atm of pressure. What
is the pressure of a 1.0 L sample that contains 2.7 g/L?
5. If 1.2 g of a gas at 6 atm of pressure dissolves in 1.0 L of
water at 25oC, how much will dissolve in 1.0 L of water at 3
atm of pressure and the same temperature?