AP
Chemistry Unit
5
Chapter
5 Gases
Daily
Multiple Guess
1.
What is the pressure, in mm Hg, of a gas that has a pressure of 15.0 lb/in2?
a.
0.113 b. 776 c. 1.02 d.
27.6
2.
A balloon with an internal pressure of 300 torr rises
to a height of 30,000 feet, where the pressure is 15 torr.
Assuming temperature remains constant, calculate by what ratio did the volume
change?
a. 25:1 b.
1000:1 c.20:1 d. 1.85:1
3.
A 0.90 L sample of helium is heated from 68°F to 68°C. At constant pressure,
what volume does this sample occupy at 68°C?
a.
1.1 b.
1.6 L c.
0.9 L d. 2.7 L
4.
A 3.00 L sample of xenon is heated from 100°F to 200°F,
and an initial pressure 70.0 cm to 120 cm of Hg. What is the final volume, in
L, of the gas?
a. 1.80 L b. 2.06
L c. 3.00 L d. 6.00 L
5.
How many moles of an ideal gas are present in a sample at 1.25 L at 311 K and a
pressure of 2500 lb/in2?
a.
8.35 b. 5.10 c. 32.8 d.
1.02
6.
A 3.25 L sample of a gas at 80.0 degrees C is heated until a final volume of
32.5 L is reached. What is the final temperature of the gas in Kelvin at
constant pressure?
a.
3.53 x 103 b. 151 c. 1.08 x 103 d. 1.34 x 103
7.
Calculate the number of grams of acetylene (C2H2) in a
30.0 L cylinder at a temperature of 20.0°C and a pressure equal to 2500 lb/in2.
a.
8.47 x 103 b. 1000 c. 5.52 x 103 d. 2.40 x 103
8.
A 50.0 L cylinder at a temperature of 47°C and a pressure of 50.0 atm contains how many molecules per cm3?
a.
1.15 x 1021 b. 2.30 x
1022 c. 2.30 x 1019
d. 6.75 x 1018
9.
A 50.0 L cylinder of Cl2 at 20.0°C and a pressure of 103,401 torr springs a leak. The following
day the pressure is found to be 41,361 torr. How many
moles of chlorine gas escaped during this time?
a.
170 b. 280 c. 85.0 d.
113
10.
Tin reacts with hydrochloric acid to produce hydrogen gas and tin (II)
chloride. How many liters of hydrogen gas are produced at 27.0°C and a pressure
of 710 torr, if 2.80 g of tin reacts with excess
hydrochloric acid?
a.
0.620 b. 0.320 c. 2.00 d. 1.25
11.
How many cm3 of carbon tetrachloride are produced when 8.0 L of
chlorine are allowed to react with 0.75 L of methane at STP?
4Cl2(g)
+ CH4(g) → 4HCl(g)
+ CCl4(g)
a.
1500 b. 750 c. 3000 d. 1080
12.
Calculate the density, in g/L, of sulfur dioxide (g) at 37°C and a pressure of
1440 torr.
a.
6.0 b. 0.60 c. 2.38 d. 4.76
13.
Calculate PT, in atm, for three different
gases at partial pressures of 144.0 cm, 800.0mm, and 1.3 m of Hg.
a.
1.90 b. 2.58 c. 1.06 d. 4.66
14.
1.0 L of hydrogen gas is collected over water at 308 K at a pressure of 728 torr. How many grams of iron are required to react with
excess HCl(aq) to produce this volume of
hydrogen gas? The vapor pressure of water is 42.2 torr.
The products of the reaction are iron (II) chloride and hydrogen gas.
a.
4.7 g b. 2.35 g c. 2.0 g d. 1.3 g
15.
Gas A diffuses twice as fast as gas B. Gas B has a molecular weight of 60.0
g/mole. What is the molar mass of gas A?
a.
15.0 b. 120 c. 30 d.
90
16.
If gas B effuses four times as fast as gas A, what is the ratio of the molar
masses (A/B)?
a.
2:1 b. 4:1 c. 16:1 d. 8:1
17.
Using the van der Waals equation, calculate the pressure exerted by 10 g of
methane (CH4) in a 2.1 L container at 330 K. a = 2.253 L2 atm/mol2,
b = 0.0458 L/mole. Calculate using the ideal gas equation and find the
difference between the ideal gas pressure and van der
Waals pressure.
a.
2.0 b. 0.5 c. 0.1 d. 1.5
Free Response
18. In a science demonstration,
19. How much force is required to inflate a
high pressure bicycle tire to 95 pounds per square inch (655 kPa) with a
hand pump that has a plunger with area of 5.0 cm2?
20. An object exerts a force of 500. N and
sits on an area of 4.5 m X 1.5 m. Calculate the amount of
pressure exerted by the object in torr.
21. What would the volume of gas contained in an expandable 1.0 L cylinder at 15 MPa (1 MPa 106 Pa) be at 1 atm (assuming constant temperature)?
22. A sample tube containing 103.6 mL of CO gas at 20.6 ton is connected to an evacuated 1.13
liter flask. (The new volume is the sum of those of the tube and flask.) What
will the pressure be when the CO is allowed into the flask?
23. A gas has a pressure of 3.2 atm and occupies a volume of 45 L. What will the pressure
be if the volume is compressed to 27 L at a constant temperature?
24. The volume of a gas (held at constant
pressure) is to be used “as a thermometer.” If the volume at 0.0 C is 75.0 cm3
what is the temperature when the measured volume is 56.7 cm3?
25. If a 16.6 L sample of a gas contains 9.2
moles of F2, how many moles of gas would there be in a 750 mL sample at the same temperature and pressure?
26. A 11.2 L sample of gas is determined to
contain 0.50 moles of N2. At the same temperature and pressure how
many moles of gas would there be in a 20. L sample?
27. Calculate the volume occupied at 87.0°C
and 950. torr by a quantity
of a. gas which occupied 20.0 L at 27.0°C and 570. torr.
28. What is the volume of 16 g of sulfur
dioxide at 20.0°C and
740 torr pressure?
29. A quantity of gas at 27.0°C is heated in
a closed vessel until the pressure is doubled. To what temperature is the gas
heated’?
30. A weather balloon is filled with 0.295 m3
of helium on the ground at 18°C and 756 torr.
What will the volume of the balloon be at an altitude of 10 km where the
temperature is -48°C and the pressure is 0.14 atm?
31. A sample of gas occupies 3.8 L at 15°C
and 1.00 atm. What does the temperature need to be
for the gas to occupy 8.3 L at 1.00 atm?
32. Calculate the volume of O2
present in a sample containing 0.89 moles of O2 at a temperature of
40°C and a pressure of 1.00 atm.
33. What pressure would be exerted by 50.0 g
of He at 25.0°C in a volume of 350. L?
34. A 10.5 g sample of CO2 gas
occupies a volume of 7.00 L at a pressure of 1.5 atm.
What must be the temperature of the gas?
35. Calculate the number of moles present in
a quantity of gas which occupies 26,880 mL at 564°C
and 380. torr.
36. The density of liquid nitrogen is 0.808
g/mL at -196°C. What volume of nitrogen gas at STP
must be liquefied to make 10.0 L of liquid nitrogen?
37. Calculate the volume occupied by 2.5 mol
of an ideal gas at STP.
38. A hydrocarbon (compound containing only
hydrogen and carbon) was analyzed to be 85.7 mass percent carbon and 14.3 mass
percent hydrogen. At 26°C and 745 torr pressure a
sample with a volume of 1.13 L had a mass of 1.904 g. Determine
the molecular formula. (You may wish to review Chapter 3.)
39. An
unknown gas has a density of 7.06 g/L at a pressure of 1.50 atm
and 280 K. Calculate the molar mass of the gas.
40. HC1(g)
can be prepared by reaction of NaC1 with H2S04. What mass
of NaC1 is required to prepare enough HC1 to fill a 340.
mL cylinder to a pressure of
151 atm at 20.0°C?
41. A sample of 26.81 ni.L
of 0.1000 M HCI reacts completely with a rock containing 3.164 g CaCO3.
What would be the maximum theoretical volume of CO2 collected at
30°C and 1.00 atm?
42. A 27.7 mL
sample of C02(g) was collected over water
at 25.0°C and 1.00 atm. What is the pressure in torr due to C02(g)?
(The vapor pressure of water at 25.00 C is 23.8 torr.)
What will the volume of C02(g) be at the
same temperature and pressure after removing the water vapor’?
43. A gas-tight vessel has a volume of 1000m3.
It is filled with air at
27°C and 1.00 atm. Assuming air to be 79%
N2 and 21% O2
(by volume), calculate the following:
a. partial pressure of N2 b. partial pressure
of O2
44. A gaseous mixture of O2, H2 . and N2 has a total pressure of
1.50 atm and contains 8.20 g of each gas. Find the
partial pressure of each gas in the mixture.
45. The mole fraction of argon in dry air is
0.00934. How many liters of air at STP will contain enough argon to fill a 35.4
L cylinder to a pressure of 150. atm at 20°C?
46. Assume that the mole fraction of
nitrogen in the air is 0.8902. Calculate the partial pressure of N2 in
the air when the atmospheric pressure is 820 torr.
47. Calculate the root mean square speed of
O2 gas
molecules at 300. K.
48. What happens to the average kinetic
energy of a mole of an ideal gas if:
a. the volume is
doubled resulting in a decrease in pressure at constant temperature?
b. the temperature is increased at a
constant pressure?
c. absolute zero is obtained’?
49. Ammonia
(NH3(g)) and HC1(g) react to form a solid
precipitate. NH4C1. Two cotton swabs, one moistened with ammonia and
the other with hydrochloric acid, are inserted into opposite ends of a 1 meter
long glass tube. How far from the hydrochloric acid end of the tube would you
expect to see the white NH4C1 precipitate’?
50. Calculate the rate of effusion of PH3
molecules through a small
opening
if NH3
molecules pass through the same opening at a rate of 8.02 cm3/s.
Assume the same temperature and equal partial pressures of the two gases.
51. What are the relative rates of diffusion
for methane. CH4 and oxygen,O2? If O2(g)
travels 1.00m in a certain amount of time, how far will methane be able to
travel under the same conditions’?
52. Which gas effuses faster: Ne
or C02? How much faster?
53. Which gas would effuse faster. Ar or O2. How much faster?
54. Calculate the pressure exerted by 1 mole
of Xe(g)
using the ideal gas law and van der
a. in
a 100.0 L container at 23°C and b.
in a 1.000 L container at 23°C.
55. Calculate the pressure exerted by 100. moles of Cl2 gas in a 20. L
container at 25.0° C using van der Waal’s equation and constants
in Table 5.3 of your textbook.
56. Why are all gases not perfect gases?