Gas laws Review
Boyles’ Law
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8)
1.00 L of a gas at standard temperature and pressure is compressed to 473 mL. What is the new pressure of the
gas?
In a thermonuclear device, the pressure of 0.050 liters of gas within the bomb casing reaches 4.0 x 106 atm.
When the bomb casing is destroyed by the explosion, the gas is released into the atmosphere where it reaches a
pressure of 1.00 atm. What is the volume of the gas after the explosion?
Synthetic diamonds can be manufactured at pressures of 6.00 x 104 atm. If we took 2.00 liters of gas at 1.00 atm
and compressed it to a pressure of 6.00 x 104 atm, what would the volume of that gas be?
The highest pressure ever produced in a laboratory setting was about 2.0 x 106 atm. If we have a 1.0 x 10-5 liter
sample of a gas at that pressure, then release the pressure until it is equal to 0.275 atm, what would the new
volume of that gas be?
Atmospheric pressure on the peak of Mt. Everest can be as low as 150 mm Hg, which is why climbers need to
bring oxygen tanks for the last part of the climb. If the climbers carry 10.0 liter tanks with an internal gas pressure
of 3.04 x 104 mm Hg, what will be the volume of the gas when it is released from the tanks?
Part of the reason that conventional explosives cause so much damage is that their detonation produces a strong
shock wave that can knock things down. While using explosives to knock down a building, the shock wave can be
so strong that 12 liters of gas will reach a pressure of 3.8 x 104 mm Hg. When the shock wave passes and the
gas returns to a pressure of 760 mm Hg, what will the volume of that gas be?
Submarines need to be extremely strong to withstand the extremely high pressure of water pushing down on
them. An experimental research submarine with a volume of 15,000 liters has an internal pressure of 1.2 atm. If
the pressure of the ocean breaks the submarine forming a bubble with a pressure of 250 atm pushing on it, how
big will that bubble be?
Divers get “the bends” if they come up too fast because gas in their blood expands, forming bubbles in their blood.
If a diver has 0.05 L of gas in his blood under a pressure of 250 atm, then rises instantaneously to a depth where
his blood has a pressure of 50.0 atm, what will the volume of gas in his blood be? Do you think this will harm the
diver?
Boyles’ Law
ANSWERS
1)
2)
3)
5)
6)
7)
8)
2.11 atm
2.0 x 105 L
72.7 L
2.0 x 103 L
600 L
72 L
V = 0.25 L, yes
Charles’ Law Worksheet
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7)
The temperature inside my refrigerator is about 40 ºCelsius. If I place a balloon in my fridge that
initially has a temperature of 220 ºC and a volume of 0.5 liters, what will be the volume of the
balloon when it is fully cooled by my refrigerator?
A man heats a balloon in the oven. If the balloon initially has a volume of 0.4 liters and a
temperature of 20 ºC, what will the volume of the balloon be after he heats it to a temperature of
250 ºC?
On hot days, you may have noticed that potato chip bags seem to “inflate”, even though they have
not been opened. If I have a 250 mL bag at a temperature of 19 ºC, and I leave it in my car which
has a temperature of 600 ºC, what will the new volume of the bag be?
A soda bottle is flexible enough that the volume of the bottle can change even without opening it.
If you have an empty soda bottle (volume of 2 L) at room temperature (25 ºC), what will the new
volume be if you put it in your freezer (-4 ºC)?
Some students believe that teachers are full of hot air. If I inhale 2.2 liters of gas at a temperature
of 180 ºC and it heats to a temperature of 380 ºC in my lungs, what is the new volume of the gas?
How hot will a 2.3 L balloon have to get to expand to a volume of 400 L? Assume that the initial
temperature of the balloon is 25 ºC.
I have made a thermometer which measures temperature by the compressing and expanding of
gas in a piston. I have measured that at 1000 ºC the volume of the piston is 20 L. What is the
temperature outside if the piston has a volume of 15 L? What would be appropriate clothing for
the weather?
Charles’ Law Worksheet
ANSWER KEY
1)0.47 L
2)0.71 L
3)285 mL
4)1.81 L
5)2.35 L
6)51,800 K
7)The temperature is 298.5 K, which
corresponds to 0.50 ºC. A jacket would be
appropriate clothing for this weather.
The Ideal Gas Laws
1) If four moles of a gas at a pressure of 5.4 atmospheres
have a volume of 120 liters, what is the temperature?
2) My car has an internal volume of 2600 liters. If the sun
heats my car from a temperature of 200 ºC to a
temperature of 550 ºC, what will the pressure inside my
car be? Assume the pressure was initially 760 mm Hg.
How many moles of gas are in my car?
3) A toy balloon filled with air has an internal pressure of
1.25 atm and a volume of 2.50 L. If I take the balloon to
the bottom of the ocean where the pressure is 95
atmospheres, what will the new volume of the balloon
be? How many moles of gas does the balloon hold?
(Assume T = 285 K)
The Ideal Gas Laws ANSWERS
• 1) 1973 K
• 2) 840 mmHg; 67 moles
• 3) 0.033 L; 0.13 moles
Conceptual Question 1
• Air is contained in a sealed tank of fixed
volume. The air in the tank is initially at 20
°C and 1 atm (101.3 kPa). It is then heated
to 250 °C. What will happen to the density
of the air in the container?
– a. Density will decrease
– b. Density will not change
– c. Density will increase
– d. Insufficient information
Conceptual Question 1 ANSWER
• b. Density will not change
Conceptual Question 2
• In a cryogenics (extreme cold)
demonstration, a scientist takes a small,
partially inflated balloon out of liquid
nitrogen (at a very low temperature). As
the balloon rests on the table, it begins to
grow in size. Explain this phenomenon.
Conceptual Question 2 ANSWER
• Volume vs. temperature relationship
– Direct, when one increases so does the other
• Specifically, gas particles are moving
faster and spreading out farther from one
another
Conceptual Question 3
• Huge weather balloons partially filled with
helium are sent high into the earth’s
atmosphere to examine the air. As a
balloon rises into the air, the air pressure
outside the balloon decreases rapidly. If
the atmospheric pressure becomes onethird of its original pressure, what will
happen to the balloon volume? Explain.
Conceptual Question 3 ANSWERS
• Pressure vs. volume relationship
– Indirect, when one increases, the other
decreases and vice versa
• Balloon will grow to 3 times the size
– Less pressure on gas molecules in balloon.
They have the freedom (and energy) to move
more and take up more space
Conceptual Question 4
• Use the kinetic molecular theory to explain
why on a cold autumn morning a camper’s
air mattress may appear to be somewhat
flatter than it was when blown up the
afternoon before. Assume no leaks.
Conceptual Question 4 ANSWERS
• Volume vs. temperature relationship
– Direct
– When temp decreases so does volume
• As temp cools, gas particles move slower
= take up less space
Conceptual Question 5
1. What is the effect of increasing
temperature on the volume of a gas?
•
•
•
Increase
Decrease
Stays the Same
Conceptual Question 5 ANSWERS
• Volume increases
– Direct relationship
Conceptual Question 6
• What is the effect of increasing
temperature on the density of a gas?
– Increase
– Decrease
– Stays the Same
Conceptual Question 6 ANSWERS
• Since volume increases when temp
increases, density will decrease
– Same mass of gas taking up more space
Conceptual Question 7
• 360 kPa = __ atm = __ mmHg
Conceptual Question 7 ANSWERS
• 360 kPa = 3.55 atm = 2700 mmHg
Conceptual Question 8
• Sketch what a graph of :
– volume vs. temperature would look like for any gas.
– pressure vs. volume would look like for any gas.
– pressure vs. temperature would look like for any
gas.
Conceptual Question 8 ANSWERS
• Sketch what a graph of :
– volume vs. temperature would look like for any gas.
– pressure vs. volume would look like for any gas.
– pressure vs. temperature would look like for any
gas.
Conceptual Question 9
(not really conceptual – more like
mathematical!)
• Calculate the number of liters that 0.730
mole of CO2 occupies at STP.
Conceptual Question 9 ANSWERS
• 0.730 moles CO2 x 22.4 L = 16.4 L
1 mole
Conceptual Question 10
• At a birthday party a child sits on a
partially filled balloon, decreasing its
volume by 1/2. What is the new pressure
inside the balloon?
Conceptual Question 10
ANSWERS
• Pressure vs. volume relationship
– Indirect = when 1 increases the other
decrease
• 2 times the pressure inside the balloon
since gas particles can occupy ½ the
amount of space