1) The atmospheric pressure is 715 mm Hg. What is the pressure in torr?
A) 715 torr
B) 28.1 torr
C) 13.8 torr
D) 31.8 torr
E) 760 torr
Answer: A
Diff: 2
Page Ref: 5.2
2) What is the pressure in a gas container that is connected to an open-end U-tube manometer if
the pressure of the atmosphere is 742 torr and the level of mercury in the arm connected to the
container is 8.60 cm higher than the level of mercury open to the atmosphere?
A) 656 mm Hg
B) 733 mm Hg
C) 751 mm Hg
D) 828 mm Hg
Answer: A
3) What volume will a balloon occupy at 1.0 atm, if the balloon has a volume of 8.8 L at 4.4
atm?
A) 2.0 L
B) 0.50 L
C) 39 L
D) 13 L
E) 4.4 L
Answer: C
Diff: 2
Page Ref: 5.3
4) A gas is at 35.0°C and 3.50 L. What is the temperature at 7.00 L?
A) 343°C
B) 70.0°C
C) 616°C
D) 1.16°C
E) 17.5°C
Answer: A
Diff: 3
Page Ref: 5.3
5) A sample of 0.200 moles of nitrogen occupies 0.400 L. Under the same conditions, what
number of moles occupies 1.200 L?
A) 0.600 moles
B) 0.0667 moles
C) 2.40 moles
D) 0.0960 moles
Answer: A
6) A balloon filled with helium gas at 20°C occupies 4.91 L at 1.00 atm. The balloon is
immersed in liquid nitrogen at -196°C, while the pressure is raised to 5.20 atm. What is the
volume of the balloon in the liquid nitrogen?
A) 0.25 L
B) 3.6 L
C) 6.7 L
D) 97 L
Answer: A
7) Calculate the temperature, in K, of 2.20 moles of gas occupying 3.30 L at 3.50 atm.
A) 64.0 K
B) -209 K
C) 337 K
D) 28.0 K
Answer: A
8) A 55.0-L steel tank at 20.0°C contains acetylene gas, C2H2, at a pressure of 1.39 atm.
Assuming ideal behavior, how many grams of acetylene are in the tank?
A) 3.17 g
B) 8.20 g
C) 82.9 g
D) 1210 g
Answer: C
Diff: 3
Page Ref: 5.4
9) What is the volume of 30.0 g of argon gas at 157°C and 2.50 kPa pressure?
A) 3.87 L
B) 10.6 L
C) 393 L
D) 1070 L
Answer: D
10) A gas bottle contains 0.250 mol of gas at 730 mm Hg pressure. If the final pressure is 1.15
atm, how many moles of gas were added to the bottle?
A) 0.0262 mol
B) 0.0493 mol
C) 0.276 mol
D) 0.299 mol
Answer: B
Diff: 3
Page Ref: 5.4
11) Three identical flasks contain three different gases at standard temperature and pressure.
Flask A contains C2H4, flask B contains O3, and flask C contains F2. Which flask contains the
largest number of molecules?
A) flask A
B) flask B
C) flask C
D) All contain same number of molecules.
Answer: D
12) How many molecules of N2 are in a 400.0 mL container at 780 mm Hg and 135°C?
A) 7.01 × 1021 molecules
B) 7.38 × 1021 molecules
C) 2.12 × 1022 molecules
D) 2.23 × 1022 molecules
Answer: B
Diff: 3
Page Ref: 5.4
13) The density of krypton gas at 1.21 atm and 50.0°C is ________ g/L.
A) 0.0456
B) 0.262
C) 0.295
D) 3.82
E) 7.65
Answer: D
14) Which of the following gas samples would be most likely to behave ideally under the stated
conditions?
A) Ar at STP
B) CO at 200 atm and 25°C
C) SO2 at 2 atm and 0 K
D) N2 at 1 atm and -70°C
E) H2 at 400 atm and 25°C
Answer: A
Diff: 1
Page Ref: 5.5
15) Which of the following samples will have the greatest volume at STP?
A) 22 g Ne
B) 22 g He
C) 22 g O2
D) 22 g Cl2
E) All of these samples would have the same volume at STP.
Answer: B
16) Place the following gases in order of increasing density at STP.
F2
NH3
N2O4 Ar
A) N2O4 < Ar < F2 < NH3
B) Ar < N2O4 < F2 < NH3
C) F2 < Ar < N2O4 < NH3
D) NH3 < F2 < Ar < N2O4
E) Ar < F2 < NH3 < N2O4
Answer: D
17) What volume will 0.780 moles of Xe occupy at STP?
A) 22.4 L
B) 70.0 L
C) 43.7 atm
D) 17.5 L
E) 15.6 L
Answer: D
18) A gas occupies 22.4 L at STP and 19.0 L at 100°C and 1.50 atm pressure. How many moles
of gas did the system gain or lose?
A) 0.08 moles gained
B) 0.01 moles gained
C) 0.01 moles lost
D) 0.07 moles lost
Answer: D
19) The density of chlorine gas at 1.21 atm and 34.9°C is ________ g/L.
A) 0.0479
B) 0.295
C) 0.423
D) 1.70
E) 3.39
Answer: E
20) A 0.286-g sample of gas occupies 125 mL at 60. cm of Hg and 25°C. What is the molar mass
of the gas?
A) 5.9 g/mol
B) 44 g/mol
C) 59 g/mol
D) 71 g/mol
Answer: D
21) A mixture of 0.220 moles CO, 0.350 moles N2 and 0.640 moles Ne has a total pressure of
2.95 atm. What is the pressure of CO?
A) 1.86 atm
B) 0.649 atm
C) 0.536 atm
D) 1.54 atm
E) 0.955 atm
Answer: C
22) A gas mixture contains CO, Ar and H2. What is the total pressure of the mixture, if the mole
fraction of H2 is 0.350 and the pressure of H2 is 0.480 atm?
A) 1.37 atm
B) 0.168 atm
C) 5.95 atm
D) 0.729 atm
E) 2.1 atm
Answer: A
23) How many liters of oxygen are needed to exactly react with 19.8 g of methane at STP?
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)
A) 13.9 L
B) 27.8 L
C) 55.5 L
D) 60.5 L
Answer: C
Diff: 5
Page Ref: 5.7
24) Calcium hydride (CaH2) reacts with water to form hydrogen gas:
CaH2(s) + 2H2O(l) → Ca(OH)2(aq) + 2H2(g)
How many grams of CaH2 are needed to generate 48.0 L of H2 gas at a pressure of 0.888 atm
and a temperature of 32°C?
A) 50.7
B) 0.851
C) 143
D) 35.8
E) 71.7
Answer: D
25) Identify the gas particle that travels the fastest.
A) H2
B) N2
C) Ne
D) Cl2
E) CO
Answer: A
Diff: 1
Page Ref: 5.8
26) Calculate the ratio of effusion rates of Cl2 to O2.
A) 47.7
B) 0.451
C) 2.22
D) 1.49
E) 0.671
Answer: E
Diff: 2
Page Ref: 5.9
27) A sample of N2 effuses in 220 s. How long will the same size sample of Cl2 take to effuse?
A) 350 s
B) 138 s
C) 558 s
D) 86.8 s
E) 388 s
Answer: A
28) Zinc reacts with aqueous sulfuric acid to form hydrogen gas:
Zn(s) + H2SO4 (aq) → ZnSO4 (aq) + H2 (g)
In an experiment, 225 mL of wet H2 is collected over water at 27°C and a barometric pressure of
748 torr. How many grams of Zn have been consumed? The vapor pressure of water at 27°C is
26.74 torr.
A) 4.79 × 106
B) 0.567
C) 567
D) 431
E) 4.31 × 105
Answer: B
29) A 4.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure. What is the final
pressure in the flask if an additional 2.00 g of N2 gas is added to the flask and the flask cooled to
-55°C?
A) 0.319 atm
B) 1.05 atm
C) 1.44 atm
D) 1.96 atm
Answer: B