SECTION 14.1
LARA BEKARIAN
QUARTER 4 CHEMISTRY TECHNOLOGY PROJECT
MRS. JESSEN
MAY 20, 2013
SECTION 14.1
PROPERTIES OF GASES
OBJECTIVES
• Learn about compressibility.
• Learn factors that affect gas pressure.
• Learn kinetic theory.
• Learn why gases are easier to compress than solids or liquids.
SECTION 14.1
COMPRESSIBILITY
 Compressibility is a measure of how
much the volume of matter decreases
under pressure.
 Gases are easily compressed, or
squeezed into a smaller volume.
 Example: A car collision with an
inflated air bag cause much less
damage than a collision with a
steering wheel or dashboard because
when a person collides with an inflated
air bag, the impact forces the
molecules of gas in the bag closer
together, the compression of the gas
absorbs the energy of the impact.
SECTION 14.1
FACTORS AFFECTING GAS PRESSURE
 The factors that affect gas pressure are;
the amount of gas, volume, and
temperature.
 Example (amount of gas): When gas is
pumped into a container, the pressure
increases as more particles are added. If
the number of particles double, the
pressure doubles.
 Example (volume): A piston can be used
to force a gas in a cylinder into a smaller
volume. When the volume is decreased,
the pressure the gas exerts is increased.
 Example (temperature): An increase in
temperature causes an increase in
pressure of an enclosed gas. The
container can explode if there is too
much of an increase in the pressure.
SECTION
14.1
KENETIC ENERGY

Kinetic molecular theory: the body of theory that
explains the physical properties of matter in terms of
the motions of its constituent particles.

Gases are composed of a large number of particles
that behave like hard, spherical objects in a state of
constant, random motion.

These particles move in a straight line until they
collide with another particle or the walls of the
container.

These particles are much smaller than the distance
between particles. Most of the volume of a gas is
therefore empty space.

There is no force of attraction between gas particles
or between the particles and the walls of the
container.

Collisions between gas particles or collisions with the
walls of the container are perfectly elastic. None of
the energy of a gas particle is lost when it collides
with another particle or with the walls of the
container.
SECTION 14.1
GASES ARE EASIER TO COMPRESS
THAN SOLIDS OR LIQUIDS
 Gases are easily compressed because
of the space between the particles.
 The distance between particles in gas
is much greater than the distance
between particles in a liquid or solid,
making gas easier to compress.
THANKYOU
SECTION 14.1
CITED SOURCES
 http://www.cs.cmu.edu/~rapidproto/csc/compress.html
 http://chemed.chem.purdue.edu/genchem/topicreview
/bp/ch4/kinetic4.html
 http://www.ucolick.org/~bolte/AY4_00/week6/sun_fusion
.html