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18) A steel bottle contains argon gas at STP. What is the final pressure if the temperature is changed to
125°C?
A) 0.686 atm
B) 0.748 atm
C) 1.34 atm
D) 1.46 atm
19) A gas occupies 22.4 L at STP and 16.5 L at 100°C and 1.75 atm pressure. How many moles of gas did
the system gain or lose?
A) 0.06 moles gained
B) 0.03 moles gained
C) 0.03 moles lost
D) 0.06 moles lost
20) How many grams of CO gas are there in a 5.00-L cylinder at 4.00 × 103 mm Hg and 23°C?
A) 15.2 g
B) 29.9 g
C) 389 g
D) 2.30 × 104 g
21) What is the volume of 20.0 g of argon gas at 157°C and 2.50 kPa pressure?
A) 2.58 L
B) 7.06 L
C) 262 L
D) 716 L
22) What is the Celsius temperature of 100.0 g of chlorine gas in a 45.0-L container at 800 mm Hg?
40
A) -68°C
B) 136°C
C) 205°C
D) 410°C
23) Given three cylinders containing O2 gas at the same volume and pressure. Cylinder A is at -25°C,
cylinder B is at -20°F, and cylinder C is at 250 K. Which cylinder contains the largest mass of oxygen?
A) cylinder A
B) cylinder B
C) cylinder C
D) All cylinders contain the same mass of O2.
24) If the number of moles of gas is halved at constant temperature and volume, the pressure of the gas
A) is doubled.
B) is halved.
C) is one-fifth.
D) remains the same.
25) Given three cylinders containing O2 gas at the same volume and pressure. Cylinder A is at -35°F,
cylinder B is at -15°C, cylinder C is at 250 K. Which cylinder contains the largest mass of oxygen?
A) cylinder A
B) cylinder B
C) cylinder C
D) All cylinders contain the same mass of O2.
26) A 0.529-g sample of gas occupies 125 mL at 60. cm of Hg and 25°C. What is the molar mass of the gas?
A) 11 g/mol
B) 81 g/mol
C) 110 g/mol
D) 130 g/mol
27) What is the density of chlorine gas at STP?
A) 0.316 g/L
B) 1.58 g/L
C) 2.90 g/L
D) 3.16 g/L
28) Which of the following would have a density of 3.04 g/L at 7.0°C and 0.987 atm?
A) Ar
B) Cl2
C) He
D) N2
29) The action of some commercial drain cleaners is based on the following reaction:
2 NaOH(s) + 2 Al(s) + 6 H2O(l) → 2 NaAl(OH)4(s) + 3 H2(g)
What is the volume of H2 gas formed at STP when 4.32 g of Al reacts with excess NaOH?
A) 2.39 L
B) 3.59 L
C) 5.38 L
D) 5.88 L
30) How many liters of oxygen are needed to exactly react with 27.8 g of methane at STP?
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)
A) 19.5 L
B) 39.0 L
C) 77.9 L
D) 85.0 L
31) When 12.0 g of zinc metal reacts with excess HCl, how many liters of H2 gas are produced at STP?
A) 0.243 L
B) 0.486 L
C) 4.11 L
D) 8.23 L
32) How many grams of XeF6 are required to react with 0.579 L of hydrogen gas at 2.46 atm and 45°C in
the reaction shown below?
XeF6(s) + 3 H2(g) → Xe(g) + 6 HF(g)
A) 3.65 g
B) 4.46 g
C) 13.4 g
D) 40.2 g
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33) One mole of which gas has the greatest density at STP?
A) Kr
B) CO2
C) Ar
D) All three gases have the same density.
34) At STP how many grams of Mg are required to produce 245 mL of H2 in the reaction shown below?
Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq)
A) 245 g
B) 0.266 g
C) 0.245 g
D) 29 g
35) A balloon contains 0.76 mol N2, 0.18 mol O2, 0.031 mol He and 0.026 mol H2 at 739 mm Hg. What is
the partial pressure of O2?
A) 19 mm Hg
B) 23 mm Hg
C) 130 mm Hg
D) 560 mm Hg
36) What is the total pressure in a 8.00-L flask which contains 0.127 mol of H2(g) and 0.288 mol of N2(g) at
20.0°C?
A) 0.382 atm
B) 0.681 atm
C) 0.866 atm
D) 1.25 atm
37) A 1.000 kg sample of nitroglycerine, C3H5N3O9, explodes and releases gases with a temperature of
44
1985°C at 1.400 atm. What is the volume of gas produced?
4 C3H5N3O9(s) → 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g)
A) 583.1 L
B) 2770 L
C) 3716 L
D) 4225 L
38) In the laboratory, hydrogen gas is usually made by the following reaction:
Zn(s) + 2 HCl(aq) → H2(g) + ZnCl2(aq)
How many liters of H2 gas, collected over water at an atmospheric pressure of 752 mm Hg and a
temperature of 21.0°C, can be made from 2.566 g of Zn and excess HCl? The partial pressure of water
vapor is 18.65 mm Hg at 21.0°C.
A) 0.0701 L
B) 0.939 L
C) 0.959 L
D) 0.981 L
39) A 0.700 g sample containing Ag2O and inert material is heated, causing the silver oxide to decompose
according to the following equation:
2 Ag2O(s) → 4 Ag(s) + O2(g)
If 13.8 mL of gas are collected over water at 27°C and 1.00 atm external pressure, what is the percentage
of silver oxide in the sample? The partial pressure of water is 26.7 mm Hg at 27°C.
A) 8.93%
B) 17.9%
C) 35.9%
D) 38.4%
40) A 10.0-L flask containing He, 1.00 mole of Ar, and 3.00 mole of Ne has a total pressure of 24.5 atm at
25°C. How many moles of He are in the flask?
A) 6.00 mol
B) 10.0 mol
C) 10 .0 mol
D) 119 mol
41) The partial pressures of CH4, N2, and O2 in a sample of gas were found to be 143 mmHg, 469 mmHg,
and 251 mmHg, respectively. Calculate the mole fraction of oxygen.
A) 0.410
B) 0.291
C) 2.44
D) 22.4
42) What is the average speed (actually the root-mean-square speed) of a xenon atom at 27°C?
A) 2.27 m/s
B) 7.57 m/s
C) 71.7 m/s
D) 239 m/s
43) Which of the following gases has the highest average speed at 400K?
A) NO2
B) SO2
C) OF2
D) SF6
44) Which of the following gases has the lowest average speed at 25°C?
A) C2H6
B) H2Se
C) PH3
D) F2
45) Which of the following gases has the highest average speed at 400K?
A) HCN
B) O2
C) Xe
D) BF3
46) Which of the following gases has the lowest average speed at 25°C?
A) He
B) BF3
C) H2
D) NH3
47) What is the temperature of SO2 gas if the average speed (actually the root-mean-square speed) of the
molecules is 750 m/s?
A) 1.92 K
B) 1.44 × 103 K
C) 1.92 × 103 K
D) 1.44 × 106 K
48) Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K. Cylinder A contains Ne,
cylinder B contains F2, and cylinder C contains Cl2. According to the kinetic molecular theory, which gas
has the highest average speed?
A) Ne
B) F2
C) Cl2
D) All have identical average speeds
49) Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K. Cylinder A contains
HCN, cylinder B contains CO2, and cylinder C contains O3. According to the kinetic molecular theory,
which gas has the highest pressure?
A) HCN
B) CO2
C) O3
D) All have identical pressures
50) Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K. Cylinder A contains He,
cylinder B contains CO2, and cylinder C contains SO2. According to the kinetic molecular theory, which
gas has the highest density?
A) He
B) CO2
C) SO2
D) All have identical densities
51) Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K. Cylinder A contains
HCN, cylinder B contains NO2, and cylinder C contains O3. According to the kinetic molecular theory,
which gas has the highest average kinetic energy?
A) HCN
B) NO2
C) O3
D) All have identical average kinetic energies
52) If NO2 and NH3 are allowed to effuse through a porous membrane under identical conditions, the
rate of effusion for NH3 will be ________ times that of CO2.
A) 0.37
B) 0.61
C) 1.6
D) 2.7
53) The mixing of different gases by random molecular motion with frequent collisions is called
A) Dalton’s law.
B) compressibility.
C) diffusion.
D) effusion.
54) A process by which gas molecules escape through a tiny hole in a membrane into a vacuum without
collisions is called
A) Boyle’s law.
B) diffusion.
C) effusion.
D) compressibility.
55) Which one of the following gases will have the highest rate of effusion?
A) HCN
B) CO2
C) Ar
D) SO2
56) Which one of the following gases will have the lowest rate of effusion?
A) Ne
B) NO2
C) Ar
D) SO2
57) A carbon dioxide monitoring product provides a reading of 202 ppm. Calculate the percent carbon
dioxide by volume.
A) 2.02
B) 0.0202
C) 0.202
D) 20.2
58) A greenhouse gas of greatest concern that is from human activities is
A) oxygen.
B) fluorine.
C) radon.
D) methane.
59) Refrigeration and air conditioning are a source of greenhouse gases such as
A) CHClF2.
B) Ne.
C) HBr.
D) H2.
60) Historical records of greenhouse gases can be found in
A) polar ice caps.
B) oil from the ground.
C) the Alps.
D) the Dead Sea Scrolls.
In the diagram below, nitrogen molecules are represented by unshaded spheres, oxygen molecules by
gray spheres, and chlorine molecules by black spheres.
61) If the total pressure in the container is 400. mm Hg, what is the partial pressure of nitrogen?
A) 40.0 mm Hg
B) 80.0 mm Hg
C) 120. mm Hg
D) 200. mm Hg
62) If the total pressure in the container is 800. mm Hg, what is the partial pressure of oxygen?
A) 80.0 mm Hg
B) 160. mm Hg
C) 240. mm Hg
D) 400. mm Hg
63) If the total pressure in the container is 100. mm Hg, what is the partial pressure of chlorine?
A) 10.0 mm Hg
B) 20.0 mm Hg
C) 30.0 mm Hg
D) 50.0 mm Hg
10.3 Short Answer Questions
1) Under the same pressure and temperature conditions, the level of water inside a barometer will be
________ than the level of mercury inside the barometer by a factor equal to the ratio of the density of
________ over the density of ________.
2) At an atmospheric pressure of 745 mm Hg, what is the pressure of He gas inside a cylinder that is
attached to an open-end manometer in which the level of mercury in the open side of the manometer is
25 mm Hg higher than the side that is attached to the gas cylinder?
3) The pressure in a container of gas connected to an open-end mercury manometer in which the mercury
level is 22 cm lower in the side open to the atmosphere and the atmospheric pressure is 734 mm Hg is
________ mm Hg.
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4) One mole of gas at 25°C in a 3.0-L flask has a ________ pressure than one mole of gas at 25°C in a 14.0–
L flask.
5) One mole of gas at 25°C has a ________ volume than one mole of gas at standard temperature.
6) At STP if 1.00 mole of gas occupies 22.4 L then 0.200 mole of gas would occupy ________ L under the
same conditions.
7) When using the ideal gas law the temperature must be expressed in ________.
8) If one mole of gas occupies 22.4 L at STP the same gas would occupy ________ than 22.4 L at 60°C and
630 mm Hg.
9) To two significant figures, by what factor will the pressure of an ideal gas change if the temperature of
the gas is changed from 100°C to 200°C?
10) If 0.40 mol of NaN3 reacts completely in the reaction shown below, then ________ L of N2 will be
produced at STP.
2 NaN3(s) → 2 Na(s) + 3 N2(g)
11) If 1.0 mol of N2 and 3.0 mol of H2 in a closed container initially at STP react completely in the reaction
shown below, then the final pressure in the flask will be ________ atm at 273 K.
N2(g) + 3 H2(g) → 2 NH3(g)
12) At STP the number of liters of O2 required to react with 11.2 liters of CH4 to form only CO2 and H2O
is ________ liters.
13) In a flask containing 2.00 mol of Ar, 3.00 mol of HCN, and 5.00 mol of N2 at STP the partial pressure
of He is ________ mm Hg.
14) If 1.0 gram each of Cl2, CO2, N2, and O2 are contained in a 5-L flask, the gas with the highest partial
pressure is ________.
15) According to the kinetic molecular theory of gases, the volume of the gas particles (atoms or
molecules) is ________ compared to the volume of the container in which the gas particles are held.
16) According to the kinetic molecular theory of gases, at 290 K the average kinetic energy of O2 is
________ the average kinetic energy of NO2.
17) According to the kinetic molecular theory of gases, what is the force of attraction of one CO molecule
for another CO molecule?
18) According to the kinetic molecular theory of gases, raising the temperature of a gases increases the
average kinetic energy and the frequency of ________.
19) At 298 K which is larger rate of effusion or rate of diffusion?
20) According to Graham‘s law, the rate of effusion of a gas is inversely proportional to the ________.
21) Gases do not behave ideally under conditions of ________ pressure and ________ temperature.
22) The region of the atmosphere that is closest to the earth’s surface is the ________.
23) The burning of sulfur-containing coal can lead the formation of ________ which is emitted into the
atmosphere.
24) The molecule believed to be most responsible for global warming is ________.
25) The secondary pollutants in photochemical smog are ________.