Honors Chemistry
Name ________________________________
Chapter 11: Gas Laws WS II
Date _____/_____/_____
Period _____
This worksheet uses all of the gas laws that we have covered – Boyles, Charles, Dalton’s, Combined, Molar
Volume (gas stoichiometry), and Ideal. Provide the formula, plug in values with units, and solve the equation.
1. A 2.00 L sample of a gas originally at 25 degrees C and a pressure of 700. torr is allowed to expand to a
volume of 5.00 L. If the final pressure of the gas is 585 torr, what is its final temperature in Celsius?
P1 = 700. torr
o
V1 = 2.00 L
T2 = T1P2V2 = (298 K)(585 torr)(5.00 L) = 623 K = 350. C
o
T1 = 25 C = 298 K
P1V1
(700. Torr)(2.00 L)
P2 = 585 torr
V2 = 5.00 L
T2 = ?
2. A gas has a volume of 350. mL at 740. torr. How many milliliters will the gas occupy at 900. torr if the
temperature remains constant?
P1 = 740. torr
V1 = 350. mL
V2 = P1V1 = (740. torr)(350. mL) = 288 mL
P2 = 900. torr
P2
(900. torr)
V2 = ?
3. Calculate the number of liters occupied by the following at STP:
a. 0.200 moles of oxygen
0.200 moles O2
22.4 L O2
1 mole O2
= 4.48 L O2
or PV = nRT or V1 = V2
n1
n2
b.
12.4 grams of chlorine gas
12.4 grams Cl2
1 mole Cl2
70.90 g Cl2
22.4 L Cl2
1 mole Cl2
= 3.92 L Cl2
or PV = nRT or V1 = V2
n1
n2
c.
a mixture of 0.100 moles of nitrogen gas and 0.500 moles of oxygen gas
0.100 moles N2 gas + 0.500 moles O2 gas = 0.600 moles gas
0.600 moles gas
22.4 L gas
1 mole gas
= 13.4 L gas
or PV = nRT or V1 = V2
n1
n2
4. From the volume, temperature and pressure listed below, calculate the number of moles for the gas:
3
750.0 cm at 27.0 degrees C and 99.0 kPa.
P
V
n
T
=
=
=
=
99.0 kPa = 0.977 atm
3
750.0 cm = 750.0 mL = 0.7500 L
?
o
27.0 C = 300. K
n = PV = (0.977 atm)(0.7500 L)(mole ▪ K)
RT
(0.0821 L ▪ atm)(300. K)
n = 0.0298 moles
5. A balloon has a volume of 2.0 L indoors at a temperature of 25.0 degrees C. If it is taken outdoors on a
very cold day when the temperature is –28.9 degrees C, what will its volume be in liters? Assume a
constant air pressure within the balloon.
V1 = 2.0 L
o
T1 = 25.0 C = 298 K
V2 = V1T2 = (2.0 L)(244 K) = 1.6 L
V2 = ?
T1
(298 K)
o
T2 = –28.9 C = 244 K
6. A gas exerts a pressure of 350.0 torr at 20.0 degrees C. How many torr will it exert if its temperature is
raised to 40.0 degrees C without a change in the volume of the container?
P1 = 350.0 torr
o
T1 = 20.0 C = 293 K
P2 = P1T2 = (350.0 torr)(313 K) = 374 torr
P2 = ?
T1
(293 K)
o
T2 = 40.0 C = 313 K
7. If a 0.0500 L sample of gas exerts a pressure of 450.0 torr at 35.0 degrees C, how many milliliters will it
occupy at STP?
P1 = 450.0 torr
V1 = 0.0500 L
V2 = P1V1T2 = (450.0 torr)(0.0500 L)(273 K) = 0.0262 L = 26.2 mL
o
T1 = 35.0 C = 308 K
T1P2
(308 K)(760. torr)
P2 = 760. torr
V2 = ?
T2 = 273 K
8. Calculate the volume of 6.00 g of hydrogen gas at 24.0 degrees C and 1.50 atm.
6.00 g H2
P
V
n
T
1 mole H2
2.02 g H2
=
=
=
=
= 2.97 mole H2
1.50 atm
?
2.97 mole H2
o
24.0 C = 297 K
V = nRT = (2.97 mole)(0.0821 L ▪ atm)(297 K)
P
(mole ▪ K) (1.50 atm)
n = 48.3 L
9. A gas is compressed at constant temperature from a volume of 540. mL to 320. mL. If the initial pressure
was 475 torr, what is the final pressure in atm?
P1 = 475 torr = 0.625 atm
V1 = 540. mL
P2 = P1V1 = (0.625 atm)(540. mL) = 1.05 atm
P2 = ?
V2
(320. mL)
V2 = 320. mL
10. Calculate the mass of 24.5 mL of SO2 gas at STP.
24.5 mL SO2
1 L SO2
1000 mL SO2
1 mole SO2
22.4 L SO2
64.07 g SO2
1 mole SO2
= 0.0701 g SO2
or PV = nRT then convert moles to grams
11. What is the molecular mass of a gas if 300.0 mL of the gas has a mass of 0.855 g at STP?
P = 1.00 atm
V = 300.00 mL = 0.3000 L
n = ?
n = PV = (1.00 atm)(0.3000 L)(mole ▪ K)
T = 273 K
RT
(0.0821 L ▪ atm)(273 K)
n = 0.0134 mole
0.855 g
0.0134 mole
= 63.8 g
mole
or 1 mole = 22.4 L then convert moles to grams
12. A gas has a pressure of 655 torr at 35.0 degrees C. To what Celsius temperature must it be heated to
raise its pressure to 825 torr?
P1 = 655 torr
o
o
T1 = 35.0 C = 308 K
T2 = T1P2 = (308 K)(825 torr) = 388 K = 115 C
P2 = 825 torr
P1
(655 torr)
T2 = ?
13. A sample of hydrogen iodide has a mass of 2.28 g and occupies 400.0 mL at STP. What is the molecular
mass of this compound?
400.0 mL
1L
1000 mL
2.28 g
0.0179 mole
or PV = nRT
= 0.0179 mole
1 mole SO2
22.4 L SO2
then
= 127 g
mole
2.28 g / n = molecular mass
14. At what temperature will a gas sample occupy 0.850 L at 1.00 atm pressure if it occupies 400.0 mL at 32.0
degrees C and 1.00 atm?
V1 = 400.0 mL = 0.4000 L
T2 = T1V2 = (305 K)(0.850 L) = 648 K
o
T1 = 32.0 C = 305 K
V1
(0.4000 L)
V2 = 0.850 L
T2 = ?
15. If excess hydrochloric acid is added to 13.5 grams of Al, what volume of hydrogen gas will be produced if
the gas is collected at a temperature of 80.0 degrees C and a pressure of 750. torr?
2 Al
13.5 g Al
P
V
n
T
+
6 HCl

2 AlCl3
1 mole Al
26.98 g Al
=
=
=
=
+
3 H2
= 0.751 mole H2
3 mole H2
2 mole Al
750. torr = 0.987 atm
?
0.751 mole
o
80.0 C = 353 K
v = nRT = (0.751 mole)(0.0821 L ▪ atm)(353 K)
P
(mole ▪ K) (0.987 atm)
n = 22.1 L
o
o
16. A container is initially at 0.500 atm and 25 C. What will the pressure be at 125 C?
P1 = 0.500 atm
o
T1 = 25 C = 298 K
P2 = P1T2 = (0.500 atm)(398 K) = 0.668 atm
P2 = ?
T1
(298 K)
o
T2 = 135 C = 398 K
ANSWERS
1. 350. degrees C
2. 288 mL
3. a. 4.48 L
b. 3.92 L
4. 0.0298 moles
5. 1.6 L
6. 374 torr
c. 13.4 L
7.
8.
9.
10.
11.
12.
26.2 mL
48.3 L
1.05 atm
0.0701 g
63.8 g/mol
115 degrees C
13.
14.
15.
16.
127 g/mol
648 K
22.1 L
0.668 atm