2. The result of
many of these
molecular
collisions is
pressure.
PRESSURE is the
force exerted per
unit area by gas
molecules as they
strike the
surfaces around
them.
3. •Gases are composed of particles that are
moving around very fast in their
container(s).
•These particles move in straight lines until
they collides with either the container wall
or another particle, then they bounce off.
•Gas pressure is a result of the
constant movement of the gas molecules
and their collisions with the surfaces
around them.
6. BOYLE’S
States that in constant temperature
and amount of molecules, the
pressure of a fixed quantity of a
gas varies inversely with the
volume.
P1V1 = P2V2
7. As the volume of a gas sample is
decreased, gas molecules collide with
surrounding surfaces more frequently,
resulting in greater pressure.
8. •This law is named for Charles
Boyle, who studied the relationship
between pressure and volume of
a gas.
•Boyle determined that for the same
amount of a gas at constant
temperature, results in an inverse
relationship:
when one goes up, the other
comes down.
BOYLE’S
10. Organize the data in a table of
initial and final conditions.
Rearrange the gas law to solve
for unknown quantity.
Substitute the values into the
gas law equation to solve for the
unknown.
11. SAMPLE PROBLEM
Freon-12, CCl2F2, is used in
refrigeration systems. What is
the new volume (L) of a 8.0 L
sample of Freon gas initially at
550 mmHg after its pressure is
changed to 2200 mmHg at
constant T? 11
2.0 L
12. SAMPLE PROBLEM
Air trapped in a cylinder fitted
with a piston occupies 145.7
mL at 1.08 atm pressure.
What is the new volume when
the piston is depressed,
increasing the pressure by
25%? 12
?
13. PROBLEM 1
A geochemist heats a limestone
(CaCO3) sample and collects the CO2
released in an evacuated flask. After
the system comes to room
temperature, the heat produced is
291.4 mmHg. Calculate the CO2
pressure in atmospheres and
kilopascals. 13
?
14. PROBLEM 2
A diver blows a 0.75-L air bubble
10 m under water. As it rises to
the surface, the pressure goes
from 2.25 atm to 1.03 atm. What
will be the volume in mL of air in
the bubble at the surface?
14
?
15. PROBLEM 3
The pressure of a sample of
helium in a 1.00-L container
is 0.988 atm. Compute the
new pressure in mmHg if the
sample is placed in a 200 mL
container? 15
?
16. PROBLEM 4
A sample of oxygen gas
has a volume of 12.0 L at 600.
mm Hg. What is the new
pressure in atm when the
volume changes to 36.0 L?
16
?
