Transcript Gas Laws Review

GAS LAWS
PRACTICE AND REVIEW
STUDENT LEARNING OBJECTIVES
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Define pressure. Identify units of pressure and make conversions between
appropriate pressure units
Describe the relationship between pressure and volume of a fixed quantity of a
gas.
Given a change in volume, determine the resulting change in pressure (and vice
versa)
Describe the relationship between temperature and volume of a fixed quantity
of a gas.
Define “absolute zero”. Convert temperatures between Celsius and Kelvin
Given a change in temperature, determine the resulting change in volume (and
vice versa)
Describe the relationship between the volume of a gas and the quantity of the
gas (in moles).
Given a change in moles, determine the resulting change in volume (and vice
versa)
Combine Boyles, Charles, and Avogadro’s Laws to form the Ideal Gas Law
Use the ideal gas law to determine the result of changing conditions on a
sample of a gas
Use the ideal gas law to determine the quantity of a gas under a given set of
conditions
PRESSURE RESULTS FROM
• The Number of
Molecular Collisions
• The Energy of
Molecular Collisions
• Which of these is
affected by each
of the following?
• A change in the
Number of moles of
gas
• A change in
Temperature
• A change in Volume
PRESSURE UNITS
• Pressure can be
expressed in a variety
of ways
• Millimeters of mercury
(mmHg)
• Torr
• PSI (pounds per square
inch)
• Kilopascals (1000
newtons per square
meter)
• Atmospheres
• Which unit???
• Which two units are
derived from
force/area?
• Which two units are 2
names for the same
thing
• Which unit is based on
the Barometer?
• Which unit is based on
the average
atmospheric pressure
at sea level
PRESSURE UNITS
• Pressure can be
expressed in a
variety of ways
• Millimeters of mercury
(mmHg)
• Torr
• Kilopascals (1000
newtons per square
meter)
• Atmospheres
• What is the value of
standard pressure in
each of these units?
PRESSURE UNIT CONVERSIONS
• Standard Pressure:
• 760 mm Hg
• 760 torr
• 101.3 kPa
• 1.00 atm
• Convert:
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800 torr to atm
95 kPa to mmHg
100 kPa to atm
.95 atm to mmHg
775 mmHg to atm
PRESSURE VS VOLUME
• What is the
relationship
between pressure
and volume of a
fixed quantity of a
gas at a constant
temperature?
• What happens to
the pressure with an
increase in volume?
• A decrease in
volume?
• Inverse or Direct
proportion?
TEMPERATURE VS VOLUME
• What is the
relationship
between the
temperature and
volume of a fixed
quantity of a gas at
a constant
pressure?
• What happens to
the volume with an
increase in
temperature?
• A decrease in
temperature?
• Inverse or Direct
proportion?
NUMBER OF MOLES VS VOLUME
• What is the
relationship
between the
number of moles of
a gas and volume
(at a constant
temperature and
pressure)
• What happens to
the volume with an
increase in number
of moles?
• A decrease in
number of moles?
• Inverse or Direct
proportion?
BOYLES LAW
• PV = constant
• P1V1 = P2V2
A syringe contains
25.0 mL of air at 1.0
atm. What will the
pressure be if the
syringe is compressed
to 10.0 mL?
CHARLES LAW
• V/T = constant
• V2T1 = V1T2
• 0oC = 273 K
• To convert celsius to
kelvin, just add 273
• All gas law
problems must use
kelvin temperature
• A birthday helium
balloon has a
volume of 3.5L at
24oC. What will its
volume become if
you take it outside
on a winter day with
a temperature of
-6oC?
AVOGADROS LAW
• Equal volumes of
gases contain an
equal number of
moles (assuming
temperature and
pressure are
constant)
• V/n = constant
• V2n1 = V1n2
• 1.0 mole of nitrogen
gas occupies 22.4 L.
How many moles of
nitrogen gase
occupy 100.0 L?
• How many moles of
Argon gase will
occupy 100.0L?
• How many moles of
Oxygen gas will
occupy 100.0 L?
IDEAL GAS LAW
• PV = nRT
P = pressure
V = volume (L)
n = number of moles
R = .0821
atm*L/mol*K
• T = absolute temp (K)
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• Determine the
pressure exerted by
.25 mol of air in a
3.0L container at
27oC
• Determine the
volume of .50 mol of
air at 20oC and 1.1
atm
STANDARD
TEMPERATURE AND PRESSURE
• Standard
temperature = 0oC
• Standard
temperature = 273 K
• Standard pressure =
1.00 atm
• At STP, one mole of
any gas will occupy
22.4 L
• This is called
Standard Molar
Volume
STANDARD
TEMPERATURE AND PRESSURE
• Determine the
volume of4.0 moles
of air at STP
• How many moles
will occupy 50.0 L at
STP?
• At STP, one mole of
any gas will occupy
22.4 L
• This is called
Standard Molar
Volume