Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
142 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 14
Example Problem 14-2
Using Henry’s Law
If 0.24 g of a gas dissolves in 1.0 L of water at 1.5 atm of pressure,
how much of the gas will dissolve if the pressure is raised to
6.0 atm? Assume the temperature is held constant.
In this case, S 1 ϭ 0.24 g/L, P 1 ϭ 1.5 atm, and P 2 ϭ 6.0 atm. Use
Henry’s law to calculate S 2 .
Rearrange Henry’s law to solve for S 2 , then substitute the known
values into the equation and solve.
S 2 ϭ S 1
ϭ (0.24 g/L)
ϭ 0.96 g/L
Practice Problems
2. A gas has a solubility of 0.086 g/L at a pressure
of 3.5 atm. At what pressure would its solubility be 2.3 g/L?
3. The solubility of a gas changes from 0.95 g/L to 0.72 g/L. If the
initial pressure was 2.8 atm, what is the final pressure?
14.2 Solution Concentration
The concentration of a solution is a measure of the amount of
solute dissolved in a given amount of solvent or solution. A concentrated solution contains a large amount of solute. A dilute solution
contains a small amount of solute.
Using percent to describe concentration It is useful to describe
solution concentrations quantitatively, in terms of relative masses or
volumes. One method is percent by mass, which is the ratio of the
solute’s mass to the solution’s mass, expressed as a percent.
Percent by mass ϭ ᎏ
m
m
a
a
ss
ss
o
o
f
f
so
so
lu
lu
ti
t
o
e
n
ᎏ ϫ 100
Example Problem 14-3
Determining Percent by Mass
What is the percent by mass of potassium nitrate in a solution made
by mixing 5.4 g of this substance with 260.0 mL of water?
▲
6.0 atm
ᎏ
1.5 atm
P 2
ᎏ
P 1
142 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 14
Example Problem 14-2
Using Henry’s Law
If 0.24 g of a gas dissolves in 1.0 L of water at 1.5 atm of pressure,
how much of the gas will dissolve if the pressure is raised to
6.0 atm? Assume the temperature is held constant.
In this case, S 1 ϭ 0.24 g/L, P 1 ϭ 1.5 atm, and P 2 ϭ 6.0 atm. Use
Henry’s law to calculate S 2 .
Rearrange Henry’s law to solve for S 2 , then substitute the known
values into the equation and solve.
S 2 ϭ S 1
ϭ (0.24 g/L)
ϭ 0.96 g/L
Practice Problems
2. A gas has a solubility of 0.086 g/L at a pressure
of 3.5 atm. At what pressure would its solubility be 2.3 g/L?
3. The solubility of a gas changes from 0.95 g/L to 0.72 g/L. If the
initial pressure was 2.8 atm, what is the final pressure?
14.2 Solution Concentration
The concentration of a solution is a measure of the amount of
solute dissolved in a given amount of solvent or solution. A concentrated solution contains a large amount of solute. A dilute solution
contains a small amount of solute.
Using percent to describe concentration It is useful to describe
solution concentrations quantitatively, in terms of relative masses or
volumes. One method is percent by mass, which is the ratio of the
solute’s mass to the solution’s mass, expressed as a percent.
Percent by mass ϭ ᎏ
m
m
a
a
ss
ss
o
o
f
f
so
so
lu
lu
ti
t
o
e
n
ᎏ ϫ 100
Example Problem 14-3
Determining Percent by Mass
What is the percent by mass of potassium nitrate in a solution made
by mixing 5.4 g of this substance with 260.0 mL of water?
▲
6.0 atm
ᎏ
1.5 atm
P 2
ᎏ
P 1