Quick Write p126:
What happens to a
plastic bottle placed in
the freezer overnight?
Class Norms
 Honor
time limits
 Actively
participate (Have S.W.A.G.)
 Listen
respectfully to your colleagues
 Place
cell phones on vibrate or silent mode
 Participants
may write burning questions on a
sticky note and place on the parking lot
 BE
PRESENT (Developing H.O.T.S. for
Science)
Parking Lot
Burning Issues
Questions
Comments
Ideas to Share
Charles’ Law
The Temperature-Volume
Relationship
Charles’ Law
• French chemist Jacques
Charles discovered that the
volume of a gas at constant
pressure changes with
temperature.
• As the temperature of the gas
increases, so does its volume,
and as its temperature
decreases, so does its volume.
Charles’ Law
V= Volume
k= Charles’ Law constant of Proportionality
T= Temperature in Kelvin
Explanation
• Raising the temperature of a
gas causes the gas to fill a
greater volume as long as
pressure remains constant.
• Gases expand at a constant
rate as temperature
increases, and the rate of
expansion is similar for all
gases.
Example
• If the temperature of a given
amount of gas is doubled,
for example, its volume will
also double (as long as
pressure remains
unchanged).
2V = 2kT
Charles’ Law
Charles’ Law can
be modified to a
convenient form by
solving for k.
Charles’ Law
In a sample with volume V1 &
temperature T1, changing
either volume or temperature
converts these variables to
V2 & T2.
Demonstration
of
Charles’ Law
Charles’s law
states that when
a gas is kept at
constant
pressure, the
volume of the gas
will change with
temperature.
In this
experiment,
balloons keep a
small amount of
gas (air) at an
approximately
constant
pressure.
As the balloons
are dipped into a
beaker of liquid
nitrogen (196°C; -320°F),
the air inside
them quickly
cools. The
volume of the air
inside the
balloons
decreases as
the temperature
of the balloons
decreases.
As the balloons
are dipped into a
beaker of liquid
nitrogen (196°C; -320°F),
the air inside
them quickly
cools. The
volume of the air
inside the
balloons
decreases as
the temperature
of the balloons
decreases.
As the balloons
are dipped into a
beaker of liquid
nitrogen (196°C; -320°F),
the air inside
them quickly
cools. The
volume of the air
inside the
balloons
decreases as
the temperature
of the balloons
decreases.
As the balloons
are dipped into a
beaker of liquid
nitrogen (196°C; -320°F),
the air inside
them quickly
cools. The
volume of the air
inside the
balloons
decreases as
the temperature
of the balloons
decreases.
Relationship of
Boyle’s Law and
Charles’ Law
Pressuree in kilograms per square centimeter
Temperature in kelvins
Practical
Applications
Hot AIR Balloon
The hot air that gives the hot-air
balloon its name is commonly created
by a propane gas burner that sends
powerful jets of flame into the colorful
rip-stop nylon envelope. Once the
balloon is aloft, its height is maintained
by opening and closing the blast valve,
which controls the flow of the gas to
the burner.
Charles’ Law
Calculations
Abbreviations
atm – atmosphere
mm Hg - millimeters of mercury
torr - another name for mm Hg
Pa - Pascal (kPa = kilo Pascal)
K - Kelvin
°C - degrees Celsius
Conversions
K = °C + 273
1 cm3 (cubic centimeter) = 1 mL (milliliter)
1 dm3 (cubic decimeter) = 1 L (liter) = 1000 mL
Standard Conditions
0.00 °C = 273 K
1.00 atm = 760.0 mm Hg = 101.325 kPa = 101,325 Pa
1. Calculate the decrease in temperature when 2.00 L at 20.0 °C is compressed to
1.00 L.
2. 600.0 mL of air is at 20.0 °C. What is the volume at 60.0 °C?
3. A gas occupies 900.0 mL at a temperature of 27.0 °C. What is the volume at 132.0
°C?
4. What change in volume results if 60.0 mL of gas is cooled from 33.0 °C to 5.00 °C?
5. Given 300.0 mL of a gas at 17.0 °C. What is its volume at 10.0 °C?
6. A gas occupies 1.00 L at standard temperature. What is the volume at 333.0 °C?
7. At 27.00 °C a gas has a volume of 6.00 L. What will the volume be at 150.0 °C?
8. At 225.0 °C a gas has a volume of 400.0 mL. What is the volume of this gas at 127.0
°C?
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