Gas Laws
REVIEW GAME
Question 1

A 4.3 liter tank of hydrogen is at a
pressure of 6.2 atmospheres.
What volume of hydrogen will be
available if the hydrogen is used
at pressure of 0.48 atmospheres?
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Boyle’s Law
(4.3)(6.2) = 0.48V2
V2 = 56 L
Question 2

What mass of oxygen gas must
be placed in a container with a
volume of 123.0L to produce a
pressure of 1.87 atmospheres at
28.0°C?
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Ideal Gas Law
1.87(123) = n(0.0821)(301)
n = 9.3 mol x 32 = 298 g
Question 3

What is the pressure of 20.9
grams of neon gas at -19°C in a
rigid container whose volume is
19.0 L?
Ideal Gas Law
 20.9 g Ne / 20 = 1.045 mol
 P(19) = 1.045(0.0821)(254)
 P = 1.2 atm

Question 4

A 4.45 L balloon at 14°C contains
carbon dioxide gas. If the balloon
is taken outside where the
temperature is -22°C, what
volume will the balloon occupy?
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Charles Law
4.45 / 287 = V2 / 251
V2 = 3.9 L
Question 5

A gas occupies a volume of 0.65 L
at 118.3 kPa and a temperature of
0.00°C. What volume will the gas
occupy at 2.50 atm and 50.0°C?
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Combined Gas Law
118.3 kPa x (1 atm/101.325 kPa) = 1.17 atm
1.17(0.65)/273 = 2.5V2/323
V2 = 0.36 L
Question 6

A sample of gas occupies
25 mL at -142°C. What
volume does the sample
occupy at 65°C?
Charles
 25/131 = V2/338
 V2 = 65 mL
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Question 7

When a container is filled with 6.000
grams of H2, 64.00 grams of O2, and
28.00 grams of N2, the pressure in the
container is 5412 kPa. What is the
partial pressure of O2?
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Dalton’s Law
6 g H2/2 = 3mol 64g O2/32 = 2mol 28 g N2/28 = 1mol
3+2+1 = 6 total moles
PO2 = 2/6(5412) = 1804 kPa
Question 7.5

Magnesium reacts with
hydrochloric acid


Mg + 2HCl  MgCl2 + H2
How many grams of magnesium
would I have to start with to make
3.5L of hydrogen gas at 130 kPa
and 50. degrees celsius?


130(3.5) = n (8.314)(323)
n = 0.17 mol H2 x 1/1 x 24.3 = 4.1 g
Question 8

What is the volume occupied
by 71.0 grams of chlorine gas at
STP?
Ideal Gas Law
 71 g Cl2 / 71 = 1 mol
 1V = 1(0.0821)(273)
 V = 22.4 L

Question 9

A rigid container of O2 has a
pressure of 185 kPa at a
temperature of 458 K. What is
the pressure at 283 K?
Gay Lussac’s Law
 185/458 = P2 / 283
 P2 = 114 kPa

Question 10

An unknown gas moves three
times as fast as sulfur dioxide
gas. What is the mass of the
unknown gas?
Su = 3 mu = ?
 Sso2 = 1 mso2 = 64
 1/3 = Sqrt(m/64)
 m = 7.1 g/mol

Question 11

How many moles of N2 are in a
flask with a volume of 125 mL
at a pressure of 2550 mm Hg
and a temperature of 300.0 K?
Ideal Gas Law
 2550 mm Hg ( 1 atm / 760 mm Hg) = 3.36atm
 3.36 (0.125) = n (0.0821) ( 300)
 0.0171 mol N2

Question 12

The volume of a gas is 125 mL at
254 kPa pressure. What will the
volume be when the pressure is
reduced to 1.78 psi, assuming the
temperature remains constant?
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Boyle’s Law
254 kPa ( 14.7psi / 101.325 kPa) = 36.85 psi
36.85(125) = 1.78V
V = 2590 mL
Question 13

A mixture of gases at a total pressure
of 95 kPa contains N2, CO2, and O2.
The partial pressure of CO2 is 24 kPa
and the partial pressure of the N2 is
48 kPa. What is the partial pressure
of the O2?
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Dalton’s Law
95 = 24 + 48 + Po2
Po2 = 23 kPa
Question 14

A gas, collected over water, has a
measured pressure of 1.23 atm and has
a volume of 590 mL at a temperature of
47°C. What volume will the dry gas
occupy at 25°C and standard pressure?
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Dalton and Combined
1.23 atm (101.325 kPa / 1atm ) = 124.6 kPa
124.6 kPa = Pgas + 10.62
Pgas = 113.98 kPa
113.98(590) / 320 = 101.325(V2) / 298
620 mL
Question 15

Nitrogen gas diffuses into an
empty container at a rate of
254 m/s. At what velocity will
carbon monoxide gas move at
the same temperature?
Graham
 VCO / 254 = Sqrt (28/28)
 VCO = 254 m/s

Question 16

A gas initially is present, in a balloon, at
25°C under 1 atmosphere of pressure.
The volume of the gas under these
conditions is 2.5L. What will be the new
volume of the gas if it is taken outside on
a hot day, where the temperature is
85°C and the pressure is 1.08
atmospheres?
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Combined
1(2.5)/298 = 1.08V2/358
V2 = 2.8 L
Question 17

93.0 mL of O2 gas is collected over
water at 0.930 atm and 10.0°C. What
would be the volume of this dry gas at
standard conditions?
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Dalton and Combined
0.930 atm x (101.325 kPa / 1atm) = 94.23 kPa
94.23 kPa = Pgas + 1.2281
Pgas = 93 kPa
93(93)/283 = 101.325V2/273
V2 = 82.3 mL
Question 18

If 9.0 moles of nitrogen gas will
fill a balloon that is 2.0 L in
volume at 293 K, what volume
will 28 moles of nitrogen gas fill
at the same temperature?
Avogadro’s Law
 2/9 = V2/ 28
 6.2 L

Question 19

A large cylinder of He gas, such as
that used to inflate balloons, has a
volume of 25.0 L at 22°C and 5.6
atm. How many grams of He are
in such a cylinder?
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Ideal
5.6(25) = n(0.0821)(295)
5.78 mol x 4 = 23 g
Question 20

I begin with 460 mL of oxygen
gas at a pressure of 740 mm
Hg. How many liters of gas are
present at standard pressure?
Boyle
 740(460) = 760(V2)
 V2 = 450 mL

Question 21

Calculate the pressure of a gas
whose temperature is increased
from 15°C to 25°C and whose
original pressure is 0.75 atm.
Gay Lussac
 .75/288 = P2/298
 P2 = 0.78 atm

Question 22

A sample of gas at standard
temperature and pressure is put into
an expandable container. The
original volume of the gas is 250 mL.
What is the new volume if the gas is
cooled to -15°C and the pressure is
increased to 780 mm Hg?
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Combined
(760)(250)/273 = 780V2/258
V2 = 230 mL
Question 23

A balloon is filled with 150. mL of
carbon dioxide gas at 900. mm Hg
and 25.0°C. If the pressure is held
constant, what will the new
volume be if the temperature is
raised to 75.0°C?
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Charles
150/298 = V2/348
V2 = 175 mL
Question 24

Sulfur dioxide gas can move
with a velocity of 150 m/s. How
fast will carbon dioxide gas
move at the same temperature?
Graham
 V1/150 = Sqrt(64/44)
 180 m/s

Question 25

6 moles of nitrogen gas is
placed in a 3 L container.
What volume will 18 moles of
gas occupy under the same
conditions
Avogadro
 3/6 = V2/18
9 L

Question 26

40.0g of neon gas is put into a
500. mL container at 15.0°C.
What is the pressure within the
container in kPa?
Ideal
 40 g Ne / 20 = 2 mol
 P(.5) = 2(8.314)(288)
 9580 kPa

Question 27

If a gas begins at a temperature
of 27°C and a pressure of 150
kPa, what will the new pressure
be when the temperature is
raised to 50.°C?
Gay Lussac
 150/300 = P2/323
 160 kPa

Question 28

Hydrogen gas moves with a
velocity of 400. m/s at 25°C.
What is the mass of a gas that
moves at 250. m/s at the same
temperature?
Graham
 400/250 = Sqrt(m2/2)
 5.12 g/mol

Question 29

Oxygen gas is collected over water
at 18°C at a pressure of 800. mm
Hg and a volume of 100. mL.
What is the volume of the dry gas
at STP?

Dalton and Combined

800 mmHg x (101.325 kPa/760 mmHg) = 106.7 kPa
106.7 = Pgas + 2.0644
104.6 kPa
104.6(100)/291 = 101.325V2/273
V2 = 97 mL
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Question 29

6Li + N2  2Li3N

I have 40.0 grams of lithium metal. How many
liters of nitrogen gas will react with it at 230. kPa
and 17.0 degrees celsius?
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40g/7 x 1/6 = 0.95 mol
230(v) = 0.95(8.314)(290)
V = 9.95 L
I have 25.0 L of nitrogen gas at 1.34 atm and 80.0
degrees celsius. How many grams of Li3N can I
make?
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1.34(25) = n (0.0821)(353)
n = 1.15 mol N2 x 2/1 x 35 = 80.5 g
Question 30

I have 80. grams of carbon monoxide gas, 55
grams of dinitrogen monoxide gas, and 100.
grams of diphosphorus pentoxide gas. The total
pressure of the mixture of gases is 1.67 atm.
What is the partial pressure of each gas?
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Dalton’s Law
80 g CO / 28 = 2.86 mol
55 g N2O / 44 = 1.25 mol
100 g P2O5 / 142 = 0.70 mol
TOTAL MOLES = 4.81 moles
PCO = 2.86/4.81*(1.67) = 0.99 atm
PN2O = 1.25/4.81*(1.67) = 0.43 atm
PP2O5 = 0.70/4.81*(1.67) = 0.24 atm