Name:
AP Chemistry: Unit 3: Gas Laws: AP Packet #3
Date:
Block:
1. A sample of nitrogen gas is places into a closed container. The volume is held constant while the
temperature is increased from 200 K to 400 K. Given these conditions, which of the choices below is
true?
a. The density of the gas doubles.
b. The pressure of the gas doubles.
c. The average velocity of the gas molecules doubles.
d. The number of nitrogen gas molecules increases.
e. The potential energy of the gas molecules doubles.
2. A 2.00 liter sample of argon gas at 77 °C and 720 mmHg is heated until it occupies a volume of 4.00
liters. During the expansion, the pressure is constant. What is the temperature of the gas after it has
expanded?
a. 154 °C
b. 308 °C
c. 427 °C
d. 700 °C
e. 720. °C
3. Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
If 32.7 g of Zn are allowed to react completely with an excess of HCl, how many liters of hydrogen gas,
H2, will be produced?
a. 5.6 L
b. 11.2 L
c. 22.4 L
d. 33.6 L
e. 44.8 L
4. Hydrogen gas. Liberated from a reaction between hydrochloric acid and zinc, is bubbled through water
and collected in an inverted graduated cylinder at 22 °C. The pressure of the gas mixture is 765 mmHg.
The vapor pressure of the water at 22 °C is 20 mmHg. What is the partial pressure of the hydrogen gas?
a. 22 mmHg
b. 743 mmHg
c. 745 mmHg
d. 765 mmHg
e. 785 mmHg
5. What would happen to the average kinetic energy of the molecules of a gas sample if the temperature of
the sample increased from 20 °C to 40 °C?
a. It would double.
b. It would increase.
c. It would decrease.
d. It would become half its value.
e. Two of the above.
6. Five balloons are filled up with one mole each of hydrogen, helium, nitrogen, oxygen, and argon
molecules. After some time has elapsed, which balloon will be the smallest?
a. H2
b. He
c. N2
d. O2
e. Ar
7. A 6.50 L sample of carbon monoxide is collected at 55 °C and 0.875 atm. What volume will the gas
occupy at 1.10 atm and 20 °C?
a. 1.96 L
b. 5.46 L
c. 4.62 L
d. 6.10 L
e. 9.64 L
8. PV/nRT will be less than 1 for a real gas where…
a. The gas molecules are large enough to occupy a large amount of space.
b. There is a large sample of very fast moving particles.
c. The gas molecules have a very small molar mass.
d. The gas molecules are attracted to each other.
e. The gas molecules are repelled from each other.
9. Equal numbers of moles of the gases Cl2, NO2, and CH4 are placed into an evacuated vessel equipped
with a valve. The valve has a very small hole, similar to the size of a pinhole. If the valve is opened for a
brief period of time and then closed, which will be true of the partial pressures of the gases remaining in
the flask?
a. PCl2 < PNO2 < PCH4
b. PNO2 < PCH4 < PCl2
c. PCH4 < PCl2 < PNO2
d. PNO2 < PCl2 < PCH4
e. PCH4 < PNO2 < PCl2
10. 2C(s) + O2(g)  2CO(g)
1.2 mol of O2 and 3.50 mol of solid C are placed in a 2.00 L evacuated vessel at 25 °C. If the carbon and
oxygen react completely to form CO(g), what will the final pressure be in the container?
a. 1.2 atm
b. 14.7 atm
c. 20.0 atm
d. 29.4 atm
e. 42.8 atm
11. 0.05 mol of solid HgCl2 is vaporized in a 1.00 L evacuated flask at 680 K. What is the pressure inside the
flask? (The value of the gas constant, R, is 0.0821 L atm mol-1 K-1.)
a. 0.05 atm
b. 1.00 atm
c. 2.0 atm
d. 2.8 atm
e. 3.2 atm
12. A gas sample is heated from -23.0 °C to 57.0 °C, and the volume is increased from 2.00 L to 4.00 L. If
the initial pressure is 0.125 atm, which of the following calculations will yield the correct final pressure?
a. (0.125)(2.00)(-23.0)
b.
(57)(4.00)
c. (0.125)(2.00)(330)
(57)(4.00)
(0.125)(2.00)(-23.0)
(250)(4.00)
d.
(250)(4.00)
(0.125)(2.00)(330)
e. (0.125)(4.00)(2.00)
(250)(330)
13. Several pieces of mossy zinc are added to hydrochloric acid in a filter flask fitted with a piece of rubber
tubing. The rubber tubing is submerged under water so that the gas can be bubbled through the water and
collected in a gas-collection tube. After a certain amount of hydrogen gas has been collected, the pressure
in the gas collection tube is 300 mmHg and the temperature is 20.0 °C. If the vapor pressure of water at
this temperature is 18 mmHg, what is the pressure of the hydrogen gas?
a. 318 mmHg
b. 282 mmHg
c. 320 mmHg
d. 300 mmHg
e. 18 mmHg
14. Which of the following is most likely to deviate from ideal gas behavior?
a. Cl2
b. He
c. Ar
d. O2
e. CCl2F2
15. Answer the following questions about the information given. Make sure to use full sentences and support
your answers.
Two identical sealed 1.0L containers are filled at STP with N2 and SF6.
a. Which gas has the greatest number of molecules?
b. Which gas has the greatest density?
c. Which has the highest average kinetic energy?
d. Which would deviate the most from ideal behavior?
e. If a pinhole leak was formed, which has the highest rate of effusion?