Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
129
Gases
Gases
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
13
13.1 The Gas Laws
The gas laws apply to ideal gases, which are described by the kinetic
theory in the following five statements.
• Gas particles do not attract or repel each other.
• Gas particles are much smaller than the spaces between them.
• Gas particles are in constant, random motion.
• No kinetic energy is lost when gas particles collide with each
other or with the walls of their container.
• All gases have the same kinetic energy at a given temperature.
Boyle’s Law At a constant temperature, the pressure exerted by a
gas depends on the frequency of collisions between gas particles and
the container. If the same number of particles is squeezed into a
smaller space, the frequency of collisions increases, thereby increasing the pressure. Thus, Boyle’s law states that at constant
temperature, the pressure and volume of a gas are inversely related.
In mathematical terms, this law is expressed as follows.
P 1 V 1 ϭ P 2 V 2
Example Problem 13-1
Applying Boyle’s Law
A sample of compressed methane has a volume of 648 mL at a pressure of 503 kPa. To what pressure would the methane have to be
compressed in order to have a volume of 216 mL?
Examine the Boyle’s law equation. You need to find P 2 , the new
pressure, so solve the equation for P 2 .
P 2 ϭ P 1
Substitute known values and solve.
P 2 ϭ 503 kPa
P 2 ϭ 1510 kPa
648 mL
ᎏ
216 mL
V 1
ᎏ
V 2
▲
Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
129
Gases
Gases
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
13
13.1 The Gas Laws
The gas laws apply to ideal gases, which are described by the kinetic
theory in the following five statements.
• Gas particles do not attract or repel each other.
• Gas particles are much smaller than the spaces between them.
• Gas particles are in constant, random motion.
• No kinetic energy is lost when gas particles collide with each
other or with the walls of their container.
• All gases have the same kinetic energy at a given temperature.
Boyle’s Law At a constant temperature, the pressure exerted by a
gas depends on the frequency of collisions between gas particles and
the container. If the same number of particles is squeezed into a
smaller space, the frequency of collisions increases, thereby increasing the pressure. Thus, Boyle’s law states that at constant
temperature, the pressure and volume of a gas are inversely related.
In mathematical terms, this law is expressed as follows.
P 1 V 1 ϭ P 2 V 2
Example Problem 13-1
Applying Boyle’s Law
A sample of compressed methane has a volume of 648 mL at a pressure of 503 kPa. To what pressure would the methane have to be
compressed in order to have a volume of 216 mL?
Examine the Boyle’s law equation. You need to find P 2 , the new
pressure, so solve the equation for P 2 .
P 2 ϭ P 1
Substitute known values and solve.
P 2 ϭ 503 kPa
P 2 ϭ 1510 kPa
648 mL
ᎏ
216 mL
V 1
ᎏ
V 2
▲