Answer at the bottom of the page
10.1 Multiple Choice Questions
1) Which of the following statements about gases is false?
A) Gases are highly compressible.
B) Distances between molecules of gas are very large compared to bond distances within molecules.
C) Non-reacting gas mixtures are homogeneous.
D) Gases expand spontaneously to fill the container they are placed in.
E) All gases are colorless and odorless at room temperature.
2) Of the following, __________ has a slight odor of bitter almonds and is toxic.
A) NH3
B) N2O
C) CO
D) CH4
E) HCN
3) Of the following, __________ has the odor of rotting eggs.
A) NH3
B) H2S
C) CO
D) NO2
E) HCN
4) One significant difference between gases and liquids is that __________.
A) a gas is made up of molecules
B) a gas assumes the volume of its container
C) a gas may consist of both elements and compounds
D) gases are always mixtures
E) All of the above answers are correct.
5) Molecular compounds of low molecular weight tend to be gases at room temperature. Which of the following is most likely not a gas at room temperature?
A) Cl2
B) HCl
C) LiCl
D) H2
E) CH4
6) Gaseous mixtures __________.
A) can only contain molecules
B) are all heterogeneous
C) can only contain isolated atoms
D) are all homogeneous
E) must contain both isolated atoms and molecules
7) Which of the following equations shows an incorrect relationship between pressures given in terms of different units?
A) 1.20 atm = 122 kPa
B) 152 mm Hg = 2.03 × 104Pa
C) 0.760 atm = 578 mm Hg
D) 1.0 torr = 2.00 mm Hg
E) 1.00 atm = 760 torr
8) The pressure exerted by a column of liquid is equal to the product of the height of the column times the gravitational constant times the density of the liquid, P = ghd. How high a column of water (d = 1.0 g/mL) would be supported by a pressure that supports a 713 mm column of mercury (d = 13.6 g/mL)?
A) 14 mm
B) 52 mm
C) 713 mm
D) 1.2 × 104 mm
E) 9.7 × 103 mm
9) The pressure exerted by a column of liquid is equal to the product of the height of the column times the gravitational constant times the density of the liquid, P = ghd. How high a column of methanol (d = 0.79 g/mL) would be supported by a pressure that supports a 713 mm column of mercury (d = 13.6 g/mL)?
A) 713 mm
B) 41 mm
C) 1.2 × 104 mm
D) 9.7 × 103 mm
E) 17 mm
10) If one was told that their blood pressure was 130/80, their systolic pressure was __________.
A) 130 Pa
B) 130 mm Hg
C) 80 Pa
D) 80 mm Hg
E) 80 psi
11) Which statement about atmospheric pressure is false?
A) As air becomes thinner, its density decreases.
B) Air actually has weight.
C) With an increase in altitude, atmospheric pressure increases as well.
D) The warmer the air, the lower the atmospheric pressure.
E) Atmospheric pressure prevents water in lakes, rivers, and oceans from boiling away.
12) In ideal gas equation calculations, expressing pressure in Pascals (Pa), necessitates the use of the gas constant, R, equal to __________.
A) 0.08206 atm L mol-1K-1
B) 8.314 J mol-1K-1
C) 62.36 L torr mol-1K-1
D) 1.987 cal mol-1K-1
E) none of the above
13) The first person to investigate the relationship between the pressure of a gas and its volume was __________.
A) Amadeo Avogadro
B) Lord Kelvin
C) Jacques Charles
D) Robert Boyle
E) Joseph Louis Gay-Lussac
14) Of the following, __________ is a correct statement of Boyle’s law.
A) PV = constant
B) = constant
C) = constant
D) = constant
E) = constant
15) “Isothermal” means __________.
A) at constant pressure
B) at constant temperature
C) at variable temperature and pressure conditions
D) at ideal temperature and pressure conditions
E) that = 0
16) Of the following, __________ is a valid statement of Charles’ law.
A) = constant
B) = constant
C) PV = constant
D) V = constant × n
E) V = constant × P
17) Which one of the following is a valid statement of Avogadro’s law?
A) = constant
B) = constant
C) PV = constant
D) V = constant × n
E) V = constant × P
18) The volume of an ideal gas is zero at __________.
A) 0 °C
B) -45 °F
C) -273 K
D) -363 K
E) -273 °C
19) Of the following, only __________ is impossible for an ideal gas.
A)
B) V1T1 = V2T2
C)
D)
E)
20) The molar volume of a gas at STP is __________ L.
A) 0.08206
B) 62.36
C) 1.00
D) 22.4
E) 14.7
21) How many moles of gas are there in a 45.0 L container at 25.0°C and 500.0 mm Hg?
A) 0.630
B) 6.11
C) 18.4
D) 1.21
E) 207
22) How many moles of gas are there in a 50.0 L container at 22.0°C and 825 torr?
A) 2.29 × 104
B) 1.70 × 103
C) 2.23
D) 0.603
E) 18.4
23) Standard temperature and pressure (STP), in the context of gases, refers to __________.
A) 298.15 K and 1 atm
B) 273.15 K and 1 atm
C) 298.15 K and 1 torr
D) 273.15 K and 1 pascal
E) 273.15 K and 1 torr
24) The volume of 1.20 mol of gas at 61.3 kPa and 25.0°C is __________ L.
A) 135
B) 48.5
C) 52.4
D) 108
E) 55.7
25) Sodium bicarbonate is reacted with concentrated hydrochloric acid at 37.0°C and 1.00 atm. The reaction of 6.00 kg of bicarbonate with excess hydrochloric acid under these conditions will produce __________ L of CO2.
A) 1.09 × 102
B) 2.85 × 104
C) 1.82 × 104
D) 8.70 × 102
E) 1.82 × 103
26) Sodium bicarbonate is reacted with concentrated hydrochloric acid at 25.0°C and 1.50 atm. The reaction of 7.75 kg of bicarbonate with excess hydrochloric acid under these conditions will produce __________ L of CO2.
A) 1.82 x 103
B) 2.85 x 104
C) 1.82 x 104
D) 1.50 x 103
E) 8.70 x 102
27) The volume of a sample of gas (2.49 g) was 752 mL at 1.98 atm and 62°C. The gas is __________.
A) SO2
B) SO3
C) NH3
D) NO2
E) Ne
28) The density of __________ is 0.900 g/L at STP.
A) CH4
B) Ne
C) CO
D) N2
E) NO
29) The density of NO2 in a 3.50 L tank at 780.0 torr and 37.0°C is __________ g/L.
A) 1.64
B) 9.30
C) 1.86
D) 2.92
E) 3.27
30) The density of NO2 in a 4.50 L tank at 760.0 torr and 25.0°C is __________ g/L.
A) 1.64
B) 9.30
C) 1.68
D) 1.88
E) 3.27
31) The density (in g/L) of CO2 at 1140 torr and 60.0°C is __________.
A) 2.42
B) 16.2
C) 5.70
D) 44.0
E) 10.9
32) Of the following gases, __________ has density of 2.104 g/L at 303 K and 1.31 atm.
A) He
B) Ne
C) Ar
D) Kr
E) Xe
33) A 255 mL round-bottom flask is weighed and found to have a mass of 114.85 g. A few milliliters of an easily vaporized liquid are added to the flask and the flask is immersed in a boiling water bath. All of the liquid vaporizes at the boiling temperature of water, filling the flask with vapor. When all of the liquid has vaporized, the flask is removed from the bath, cooled, dried, and reweighed. The new mass of the flask and the condensed vapor is 115.23 g. Which of the following compounds could the liquid be? (Assume the ambient pressure is 1 atm.)
A) C4H10
B) C3H7OH
C) C2H6
D) C2H5OH
E) C4H9OH
34) A sample of an unknown volatile liquid was injected into a Dumas flask (mflask = 27.0928 g, Vflask = 0.1040 L) and heated until no visible traces of the liquid could be found. The flask and its contents were then rapidly cooled and reweighed (mflask+vapor = 27.4593 g). The atmospheric pressure and temperature during the experiment were 0.976 atm and 18.0 °C, respectively. The unknown volatile liquid was __________.
A) C6H12
B) C6H14
C) C7H14
D) C7H16
E) C6H6
35) The density of air at STP is 1.285 g/L. Which of the following cannot be used to fill a balloon that will float in air at STP?
A) CH4
B) NO
C) Ne
D) N H3
E) HF
36) Removal of __________ from the natural gas both purifies the natural gas and serves as an alternative method of production of an industrially important chemical element.
A) CO2
B) H2S
C) NH3
D) As2O3
E) He
37) 10.0 grams of argon and 20.0 grams of neon are placed in a 1200.0 ml container at 25.0°C. The partial pressure of neon is __________ atm.
A) 20.4
B) 8.70
C) 0.700
D) 3.40
E) 5.60
38) 30.0 grams of argon and 15.0 grams of xenon are placed in a 120.0 ml container at 22.0°C. The partial pressure of xenon is __________ atm.
A) 8.70
B) 22.9
C) 0.700
D) 174
E) 5.60
39) A mixture of Xe, Kr, and Ar has a total pressure of 6.70 atm. What is the mole fraction of Kr if the partial pressures of Xe and Ar are 1.60 atm and 2.80 atm, respectively.
A) 0.174
B) 0.256
C) 0.343
D) 0.481
E) 0.570
40) The average kinetic energy of the particles of a gas is directly proportional to __________.
A) the rms speed
B) the square of the rms speed
C) the square root of the rms speed
D) the square of the particle mass
E) the particle mass
41) The kinetic-molecular theory predicts that pressure rises as the temperature of a gas increases because __________.
A) the average kinetic energy of the gas molecules decreases
B) the gas molecules collide more frequently with the wall
C) the gas molecules collide less frequently with the wall
D) the gas molecules collide more energetically with the wall
E) both the gas molecules collide more frequently with the wall and the gas molecules collide more energetically with the wall
42) According to kinetic-molecular theory, in which of the following gases will the root-mean-square speed of the molecules be the highest at 200°C?
A) HCl
B) Cl2
C) H2O
D) SF6
E) None. The molecules of all gases have the same root-mean-square speed at any given temperature.
43) According to kinetic-molecular theory, if the temperature of a gas is raised from 100°C to 200°C, the average kinetic energy of the gas will __________.
A) double
B) increase by a factor of 1.27
C) increase by a factor of 100
D) decrease by half
E) decrease by a factor of 100
44) Which of the following is not part of the kinetic-molecular theory?
A) Atoms are neither created nor destroyed by ordinary chemical reactions.
B) Attractive and repulsive forces between gas molecules are negligible.
C) Gases consist of molecules in continuous, random motion.
D) Collisions between gas molecules do not result in the loss of energy.
E) The volume occupied by all of the gas molecules in a container is negligible compared to the volume of the container.
45) Of the following gases, __________ will have the greatest rate of effusion at a given temperature.
A) NH3
B) CH4
C) Ar
D) HBr
E) HCl
46) The root-mean-square speed of H2S at 26.0°C is __________ m/sec.
A) 334
B) 62.4
C) 468
D) 751
E) 214
47) A tank containing both HF and HBr gases developed a leak. The ratio of the rate of effusion of HF to the rate of effusion of HBr is __________.
A) 4.04
B) 0.247
C) 2.01
D) 0.497
E) 16.3
48) At 333 K, which of the pairs of gases below would have the most nearly identical rates of effusion?
A) N2O and NO2
B) CO and N2
C) N2 and O2
D) CO and CO2
E) NO2 and N2O4
49) At STP, the ratio of the root-mean-square speed of CO2 to that of SO2 is __________.
A) 2.001
B) 2.119
C) 1.000
D) 1.207
E) 1.456
50) Arrange the following gases in order of increasing average molecular speed at 25°C.
He, O2, CO2, N2
A) He < N2 < O2 < CO2
B) He < O2 < N2 < CO2
C) CO2 < O2 < N2 < He
D) CO2 < N2 < O2 < He
E) CO2 < He < N2 < O2
51) Arrange the following gases in order of increasing average molecular speed at 25°C.
Cl2, O2, F2, N2
A) Cl2 < F2 < O2 < N2
B) Cl2 < O2 < F2 < N2
C) N2 < F2 < Cl2 < O2
D) Cl2 < F2 < N2 < O2
E) F2 < O2 < N2 < Cl2
52) Which one of the following gases would have the highest average molecular speed at 25°C?
A) O2
B) N2
C) CO2
D) CH4
E) SF6
53) A sample of oxygen gas (O2) was found to effuse at a rate equal to three times that of an unknown gas. The molecular weight of the unknown gas is __________ g/mol.
A) 288
B) 96
C) 55
D) 4
E) 10.7
54) A sample of oxygen gas was found to effuse at a rate equal to two times that of an unknown gas. The molecular weight of the unknown gas is __________ g/mol.
A) 64
B) 128
C) 8
D) 16
E) 8.0
55) A mixture of two gases was allowed to effuse from a container. One of the gases escaped from the container 1.43 times as fast as the other one. The two gases could have been __________.
A) CO and SF6
B) O2 and Cl2
C) CO and CO2
D) Cl2 and SF6
E) O2 and SF6
56) A mixture of carbon dioxide and an unknown gas was allowed to effuse from a container. The carbon dioxide took 1.25 times as long to escape as the unknown gas. Which one could be the unknown gas?
A) Cl2
B) CO
C) HCl
D) H2
E) SO2
57) How much faster does 235UF6 effuse than 238UF6?
A) 1.013 times as fast
B) 1.009 times as fast
C) 1.004 times as fast
D) 1.006 times as fast
E) 1.018 times as fast
58) An ideal gas differs from a real gas in that the molecules of an ideal gas __________.
A) have no attraction for one another
B) have appreciable molecular volumes
C) have a molecular weight of zero
D) have no kinetic energy
E) have an average molecular mass
59) A real gas will behave most like an ideal gas under conditions of __________.
A) high temperature and high pressure
B) high temperature and low pressure
C) low temperature and high pressure
D) low temperature and low pressure
E) STP
60) Which one of the following gases would deviate the least from ideal gas behavior?
A) Ne
B) CH3Cl
C) Kr
D) CO2
E) F2
61) Which noble gas is expected to show the largest deviations from the ideal gas behavior?
A) helium
B) neon
C) argon
D) krypton
E) xenon
62) The van der Waals equation for real gases recognizes that __________.
A) gas particles have non-zero volumes and interact with each other
B) molar volumes of gases of different types are different
C) the non-zero volumes of gas particles effectively decrease the amount of “empty space” between them
D) the molecular attractions between particles of gas decreases the pressure exerted by the gas
E) all of the above statements are true
63) When gases are treated as real, via use of the van der Waals equation, the actual volume occupied by gas molecules __________ the pressure exerted and the attractive forces between gas molecules __________ the pressure exerted, as compared to an ideal gas.
A) decreases, increases
B) increases, increases
C) increases, decreases
D) does not affect, decreases
E) does not affect, increases
10.2 Bimodal Questions
1) A gas at a pressure of 10.0 Pa exerts a force of __________ N on an area of 5.5 m2.
A) 55
B) 0.55
C) 5.5
D) 1.8
E) 18
2) A gas at a pressure of 325 torr exerts a force of __________ N on an area of 5.5 m2.
A) 1.8 × 103
B) 59
C) 2.4 × 105
D) 0.018
E) 2.4
3) A gas vessel is attached to an open-end manometer containing a nonvolatile liquid of density 0.791 g/mL as shown below.
The difference in heights of the liquid in the two sides of the manometer is 43.4 cm when the atmospheric pressure is 755 mm Hg. Given that the density of mercury is 13.6 g/mL, the pressure of the enclosed gas is __________ atm.
A) 1.03
B) 0.967
C) 0.993
D) 0.990
E) 0.987
4) A gas vessel is attached to an open-end manometer filled with a nonvolatile liquid of density 0.993 g/mL as shown below.
The difference in heights of the liquid in the two sides of the manometer is 32.3 mm when the atmospheric pressure is 765 mm Hg. Given that the density of mercury is 13.6 g/mL, the pressure of the enclosed gas is __________ atm.
A) 1.05
B) 1.01
C) 0.976
D) 0.993
E) 1.08
5) In a Torricelli barometer, a pressure of one atmosphere supports a 760 mm column of mercury. If the original tube containing the mercury is replaced with a tube having twice the diameter of the original, the height of the mercury column at one atmosphere pressure is __________ mm.
A) 380
B) 760
C) 1.52 × 103
D) 4.78 × 103
E) 121
6) A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is __________ atm.
A) 1.5
B) 7.5
C) 0.67
D) 3.3
E) 15
7) If 50.75 g of a gas occupies 10.0 L at STP, 129.3 g of the gas will occupy __________ L at STP.
A) 3.92
B) 50.8
C) 12.9
D) 25.5
E) 5.08
8) A sample of H2 gas (12.28 g) occupies 100.0 L at 400.0 K and 2.00 atm. A sample weighing 9.49 g occupies __________ L at 353 K and 2.00 atm.
A) 109
B) 68.2
C) 54.7
D) 147
E) 77.3
9) A sample of a gas (1.50 mol) is contained in a 15.0 L cylinder. The temperature is increased from 100°C to 150°C. The ratio of final pressure to initial pressure is __________.
A) 1.50
B) 0.667
C) 0.882
D) 1.13
E) 1.00
10) A sample of a gas originally at 25°C and 1.00 atm pressure in a 2.5 L container is subject to a pressure of 0.85 atm and a temperature of 15°C. The final volume of the gas is __________ L.
A) 3.0
B) 2.8
C) 2.6
D) 2.1
E) 0.38
11) A sample of a gas originally at 29°C and 1.25 atm pressure in a 3.0 L container is allowed to contract until the volume is 2.2 L and the temperature is 11°C. The final pressure of the gas is __________ atm.
A) 2.9
B) 2.8
C) 1.6
D) 2.1
E) 0.38
12) The reaction of 50 mL of Cl2 gas with 50 mL of CH4 gas via the equation:
Cl2 (g) + CH4 (g) → HCl (g) + CH3Cl (g)
will produce a total of __________ mL of products if pressure and temperature are kept constant.
A) 100
B) 50
C) 200
D) 150
E) 250
13) The reaction of 100 mL of Cl2 gas with 100 mL of CH4 gas via the equation:
Cl2 (g) + CH4 (g) → HCl (g) + CH3Cl (g)
will produce a total of __________ mL of products if pressure and temperature are kept constant.
A) 100
B) 50
C) 200
D) 150
E) 250
14) The reaction of 50 mL of N2 gas with 150 mL of H2 gas to form ammonia via the equation:
N2 (g) + 3H2 (g) → 2NH3 (g)
will produce __________ mL of ammonia if pressure and temperature are kept constant.
A) 250
B) 50
C) 200
D) 150
E) 100
15) The reaction of 25 mL of N2 gas with 75 mL of H2 gas to form ammonia via the equation:
N2 (g) + 3H2 (g) → 2NH3 (g)
will produce __________ mL of ammonia if pressure and temperature are kept constant.
A) 250
B) 50
C) 200
D) 150
E) 100
16) The reaction of 50 mL of Cl2 gas with 50 mL of C2H4 gas via the equation:
Cl2 (g) + C2H4 (g) → C2H4Cl2 (g)
will produce a total of __________ mL of products if pressure and temperature are kept constant.
A) 100
B) 50
C) 25
D) 125
E) 150
17) The amount of gas that occupies 60.82 L at 31.0°C and 367 mm Hg is __________ mol.
A) 1.18
B) 0.850
C) 894
D) 11.6
E) 0.120
18) The amount of gas that occupies 36.52 L at 68.0°C and 672 mm Hg is __________ mol.
A) 127
B) 1.15
C) 878
D) 24.4
E) 12.7
19) The pressure of a sample of CH4 gas (6.022 g) in a 30.0 L vessel at 402 K is __________ atm.
A) 2.42
B) 6.62
C) 0.413
D) 12.4
E) 22.4
20) The temperature of a sample of CH4 gas (10.34 g) in a 50.0 L vessel at 1.33 atm is __________ °C.
A) 984
B) -195
C) 195
D) 1260
E) -1260
21) The volume of 0.25 mol of a gas at 72.7 kPa and 15°C is __________ m3.
A) 8.1 × 10-5
B) 1.2 × 10-4
C) 4.3 × 10-4
D) 8.2 × 10-3
E) 2.2 × 10-1
22) A gas in a 325 mL container has a pressure of 695 torr at 19°C. There are __________ mol of gas in the flask.
A) 1.24 × 10-2
B) 1.48 × 10-2
C) 9.42
D) 12.4
E) 80.6
23) A 0.133 mol sample of gas in a 525 mL container has a pressure of 312 torr. The temperature of the gas is __________°C.
A) 20.3
B) -253
C) -20.3
D) 203
E) 22.4
24) The mass of nitrogen dioxide contained in a 4.32 L vessel at 48°C and 141600 Pa is __________ g.
A) 5.35 × 104
B) 53.5
C) 10.5
D) 70.5
E) 9.46 × 10-2
25) The density of ammonia gas in a 4.32 L container at 837 torr and 45.0°C is __________ g/L.
A) 3.86
B) 0.719
C) 0.432
D) 0.194
E) 4.22 × 10-2
26) The density of N2O at 1.53 atm and 45.2°C is __________ g/L.
A) 18.2
B) 1.76
C) 0.388
D) 9.99
E) 2.58
27) The molecular weight of a gas is __________ g/mol if 3.5 g of the gas occupies 2.1 L at STP.
A) 41
B) 5.5 × 103
C) 37
D) 4.6 × 102
E) 2.7 × 10-2
28) The molecular weight of a gas is __________ g/mol if 6.7 g of the gas occupies 6.3 L at STP.
A) 24
B) 3.6 × 103
C) 27
D) 3.0 × 102
E) 1.8 × 10-2
29) The molecular weight of a gas that has a density of 6.70 g/L at STP is __________ g/mol.
A) 4.96 × 102
B) 1.50 × 102
C) 7.30 × 101
D) 3.35
E) 2.98 × 10-1
30) The molecular weight of a gas that has a density of 7.10 g/L at 25.0°C and 1.00 atm pressure is __________ g/mol.
A) 174
B) 14.6
C) 28.0
D) 5.75 × 10-3
E) 6.85 × 10-2
31) The molecular weight of a gas that has a density of 5.75 g/L at STP is __________ g/mol.
A) 3.90
B) 129
C) 141
D) 578
E) 1.73 × 10-3
32) The density of chlorine (Cl2) gas at 25°C and 60. kPa is __________ g/L.
A) 20
B) 4.9
C) 1.7
D) 0.86
E) 0.58
33) The volume of hydrogen gas at 38.0°C and 763 torr that can be produced by the reaction of 4.33 g of zinc with excess sulfuric acid is __________ L.
A) 1.68
B) 2.71 × 10-4
C) 3.69 × 104
D) 2.84
E) 0.592
34) The volume of hydrogen gas at 45.0°C and 699 torr that can be produced by the reaction of 5.66 g of zinc with excess sulfuric acid is __________ L.
A) 2.84
B) 2.71 × 10-4
C) 3.69 × 104
D) 2.45
E) 0.592
35) The volume of HCl gas required to react with excess magnesium metal to produce 6.82 L of hydrogen gas at 2.19 atm and 35.0°C is __________ L.
A) 6.82
B) 2.19
C) 13.6
D) 4.38
E) 3.41
36) The volume of fluorine gas required to react with 2.67 g of calcium bromide to form calcium fluoride and bromine at 41.0°C and 4.31 atm is __________ mL.
A) 10.4
B) 210
C) 420
D) 79.9
E) 104
37) The volume of fluorine gas required to react with 4.26 g of calcium bromide to form calcium fluoride and bromine at 25.0°C and 4195 torr is __________ L.
A) 0.0943
B) 0.241
C) 241
D) 1.24 × 10-4
E) 0.124
38) What volume (mL) of sulfur dioxide can be produced by the complete reaction of 3.82 g of calcium sulfite with excess HCl (aq), when the final SO2 pressure is 827 torr at 44.0°C?
A) 7.60 x 102
B) 1.39 × 10-4
C) 1.00 × 10-3
D) 0.106
E) 5.78 × 102
39) Automobile air bags use the decomposition of sodium azide as their source of gas for rapid inflation:
2NaN3 (s) → 2Na (s) + 3N2 (g).
What mass (g) of NaN3 is required to provide 40.0 L of N2 at 25.0°C and 763 torr?
A) 1.64
B) 1.09
C) 160
D) 71.1
E) 107
40) Automobile air bags use the decomposition of sodium azide as their source of gas for rapid inflation:
2NaN3 (s) → 2Na (s) + 3N2 (g).
What mass (g) of NaN3 is required to provide 26.5 L of N2 at 22.0°C and 1.10 atm?
A) 52.2
B) 700.
C) 0.807
D) 1.21
E) 1.10
41) The Mond process produces pure nickel metal via the thermal decomposition of nickel tetracarbonyl:
Ni(CO)4 (l) → Ni (s) + 4CO (g).
What volume (L) of CO is formed from the complete decomposition of 444 g of Ni(CO)4 at 752 torr and 22.0°C?
A) 0.356
B) 63.7
C) 255
D) 20.2
E) 11.0
42) What volume (L) of NH3 gas at STP is produced by the complete reaction of 7.5 g of H2O according to the following reaction?
Mg3N2 (s) + 6H2O (l) → 3Mg(OH)2 (aq) + 2NH3 (g)
A) 3.1
B) 9.3
C) 19
D) 28
E) 0.32
43) Ammonium nitrite undergoes thermal decomposition to produce only gases:
NH4NO2 (s) → N2 (g) + 2H2O (g)
What volume (L) of gas is produced by the decomposition of 35.0 g of NH4NO2 (s) at 525°C and 1.5 atm?
A) 47
B) 160
C) 15
D) 72
E) 24
44) The thermal decomposition of potassium chlorate can be used to produce oxygen in the laboratory.
2KClO3 (s) → 2KCl (s) + 3O2 (g)
What volume (L) of O2 gas at 25°C and 1.00 atm pressure is produced by the decomposition of 7.5 g of KClO3 (s)?
A) 4.5
B) 7.5
C) 2.0
D) 3.7
E) 11
45) Since air is a mixture, it does not have a “molar mass.” However, for calculation purposes, it is possible to speak of its “effective molar mass.” (An effective molar mass is a weighted average of the molar masses of a mixture’s components.) If air at STP has a density of 1.285 g/L, its effective molar mass is __________ g/mol.
A) 26.94
B) 31.49
C) 30.00
D) 34.42
E) 28.80
46) A vessel contained N2, Ar, He, and Ne. The total pressure in the vessel was 987 torr. The partial pressures of nitrogen, argon, and helium were 44.0, 486, and 218 torr, respectively. The partial pressure of neon in the vessel was __________ torr.
A) 42.4
B) 521
C) 19.4
D) 239
E) 760
47) The pressure in a 12.2 L vessel that contains 2.34 g of carbon dioxide, 1.73 g of sulfur dioxide, and 3.33 g of argon, all at 42 °C is __________ mm Hg.
A) 263
B) 134
C) 395
D) 116
E) 0.347
48) A sample of He gas (3.0 L) at 5.6 atm and 25°C was combined with 4.5 L of Ne gas at 3.6 atm and 25 °C at constant temperature in a 9.0 L flask. The total pressure in the flask was __________ atm. Assume the initial pressure in the flask was 0.00 atm and the temperature upon mixing was 25°C.
A) 2.6
B) 9.2
C) 1.0
D) 3.7
E) 24
49) A sample of H2 gas (2.0 L) at 3.5 atm was combined with 1.5 L of N2 gas at 2.6 atm pressure at a constant temperature of 25°C into a 7.0 L flask. The total pressure in the flask is __________ atm. Assume the initial pressure in the flask was 0.00 atm and the temperature upon mixing was 25°C.
A) 0.56
B) 2.8
C) 1.0
D) 1.6
E) 24
50) In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is __________ if the partial pressures of He and Ne are 1.50 and 2.00 atm, respectively.
A) 0.179
B) 0.238
C) 0.357
D) 0.583
E) 0.417
51) A gas mixture of Ne and Ar has a total pressure of 4.00 atm and contains 16.0 mol of gas. If the partial pressure of Ne is 2.75 atm, how many moles of Ar are in the mixture?
A) 11.0
B) 5.00
C) 6.75
D) 9.25
E) 12.0
52) A gas mixture of N2 and CO2 has a total pressure of 8.00 atm and contains 12.5 mol of gas. If the partial pressure of N2 is 3.69 atm, how many moles of CO2 are in the mixture?
A) 5.77
B) 3.69
C) 4.31
D) 11.0
E) 6.73
53) A mixture of He and Ne at a total pressure of 0.95 atm is found to contain 0.32 mol of He and 0.56 mol of Ne. The partial pressure of Ne is __________ atm.
A) 1.7
B) 1.5
C) 0.60
D) 0.35
E) 1.0
54) A flask contains a mixture of He and Ne at a total pressure of 2.6 atm. There are 2.0 mol of He and 5.0 mol of Ne in the flask. The partial pressure of He is __________ atm.
A) 9.1
B) 6.5
C) 1.04
D) 0.74
E) 1.86
55) Sodium hydride reacts with excess water to produce aqueous sodium hydroxide and hydrogen gas:
NaH (s) + H2O (l) → NaOH (aq) + H2 (g)
A sample of NaH weighing __________ g will produce 982 mL of gas at 28.0°C and 765 torr, when the hydrogen is collected over water. The vapor pressure of water at this temperature is 28 torr.
A) 2.93
B) 0.960
C) 0.925
D) 0.0388
E) 925
56) SO2 (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0°C. The total pressure in the container was __________ atm.
A) 0.192
B) 4.02
C) 2.76
D) 6.78
E) 1.60
57) SO2 (5.00 g) and CO2 (5.00 g) are placed in a 750.0 mL container at 50.0°C. The partial pressure of SO2 in the container was __________ atm.
A) 2.76
B) 4.02
C) 6.78
D) 0.192
E) 1.60
58) SO2 (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0°C. The partial pressure of CO2 in the container was __________ atm.
A) 6.78
B) 2.76
C) 1.60
D) 0.192
E) 4.02
59) CO (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0°C. The total pressure in the container was __________ atm.
A) 10.3
B) 4.02
C) 6.31
D) 0.292
E) 1.60
60) CO (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0°C. The partial pressure of CO in the container was __________ atm.
A) 6.29
B) 4.02
C) 10.3
D) 0.292
E) 1.60
61) CO (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0°C. The partial pressure of CO2 in the container was __________ atm.
A) 4.02
B) 10.3
C) 1.60
D) 0.292
E) 6.31
62) The root-mean-square speed of CO at 113°C is __________ m/s.
A) 317
B) 58.3
C) 586
D) 993
E) 31.5
63) A sample of N2 gas (2.0 mmol) effused through a pinhole in 5.5 s. It will take __________ s for the same amount of CH4 to effuse under the same conditions.
A) 7.3
B) 5.5
C) 3.1
D) 4.2
E) 9.6
64) A sample of O2 gas (2.0 mmol) effused through a pinhole in 5.0 s. It will take __________ s for the same amount of CO2 to effuse under the same conditions.
A) 4.3
B) 0.23
C) 3.6
D) 5.9
E) 6.9
65) A sample of He gas (2.0 mmol) effused through a pinhole in 53 s. The same amount of an unknown gas, under the same conditions, effused through the pinhole in 248 s. The molecular mass of the unknown gas is __________ g/mol.
A) 0.19
B) 5.5
C) 88
D) 19
E) 350
66) Using the van der Waals equation, the pressure in a 22.4 L vessel containing 1.00 mol of neon gas at 100°C is __________ atm. (a = 0.211 L2-atm/mol2, b = 0.0171 L/mol)
A) 0.730
B) 1.00
C) 1.21
D) 1.37
E) 0.367
67) Using the van der Waals equation, the pressure in a 22.4 L vessel containing 1.50 mol of chlorine gas at 0.00°C is __________ atm. (a = 6.49 L2-atm/mol2, b = 0.0562 L/mol)
A) 0.993
B) 1.50
C) 0.676
D) 1.91
E) 1.48
10.3 Algorithmic Questions
1) A pressure of 1.25 atm is the same as a pressure of __________ of mm Hg.
A) 193
B) 760.
C) 950.
D) 29.9
E) 33.0
2) A closed-end manometer was attached to a vessel containing argon. The difference in the mercury levels in the two arms of the manometer was 11.8 cm. Atmospheric pressure was 783 mm Hg. The pressure of the argon in the container was __________ mm Hg.
A) 118
B) 661
C) 771
D) 795
E) 882
3) A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 667 torr. Use Boyle’s law to calculate the pressure (torr) when the volume is reduced to 7.88 L at a constant temperature of 25.0°C.
A) 846
B) 0.118
C) 5.26 × 104
D) 526
E) 1.11
4) A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 629 torr. Use Charles’s law to calculate the volume (L) the gas will occupy when the temperature is increased to 121°C while maintaining the pressure at 629 torr.
A) 10.9
B) 13.2
C) 2.07
D) 7.56
E) 48.4
5) A sample of gas (24.2 g) initially at 6.00 atm was compressed from 8.00 L to 2.00 L at constant temperature. After the compression, the gas pressure was __________ atm.
A) 12.0
B) 16.0
C) 18.0
D) 20.0
E) 24.0
6) A balloon originally had a volume of 4.39 L at 44°C and a pressure of 729 torr. The balloon must be cooled to __________°C to reduce its volume to 3.78 L (at constant pressure).
A) 38.0
B) 0.00
C) 72.9
D) 273
E) 546
7) If 3.21 mol of a gas occupies 56.2 L at 44°C and 793 torr, 5.21 mol of this gas occupies __________ L under these conditions.
A) 14.7
B) 61.7
C) 30.9
D) 91.2
E) 478
8) A gas originally at 27°C and 1.00 atm pressure in a 3.9 L flask is cooled at constant pressure until the temperature is 11°C. The new volume of the gas is __________ L.
A) 0.27
B) 3.7
C) 3.9
D) 4.1
E) 0.24
9) A sample of He gas (2.35 mol) occupies 57.9 L at 300.0 K and 1.00 atm. The volume of this sample is __________ L at 423 K and 1.00 atm.
A) 0.709
B) 41.1
C) 81.6
D) 1.41
E) 57.9
10) A sample of an ideal gas (3.00 L) in a closed container at 25.0°C and 76.0 torr is heated to 340°C. The pressure of the gas at this temperature is __________ torr.
A) 912
B) 156
C) 76.5
D) 39.5
E) 0.0253
11) At a temperature of __________°C, 0.444 mol of CO gas occupies 11.8 L at 912 torr.
A) 379
B) 73.0
C) 14.0
D) 32.0
E) 116
12) The pressure exerted by 1.5 mol of gas in a 13 L flask at 22°C is __________ kPa.
A) 560
B) 280
C) 18
D) 2.4
E) 1.0
13) A 0.325 L flask filled with gas at 0.851 atm and 19°C contains __________ mol of gas.
A) .0116
B) .0148
C) 9.42
D) 12.4
E) 80.7
14) A sample of gas (1.9 mol) is in a flask at 21°C and 697 mm Hg. The flask is opened and more gas is added to the flask. The new pressure is 782 mm Hg and the temperature is now 26°C. There are now __________ mol of gas in the flask.
A) 1.6
B) 2.1
C) 2.9
D) 3.5
E) 0.28
15) A sample of gas (1.3 mol) occupies __________ L at 22°C and 4.5 atm.
A) .079
B) .52
C) 7.0
D) 13
E) .032
16) The volume of 0.65 mol of an ideal gas at 365 torr and 97°C is __________ L.
A) .054
B) 9.5
C) 11
D) 41
E) .024
17) The volume occupied by 0.50 mol of gas at 35°C and 2.0 atm pressure is __________ L.
A) 38
B) 6.3
C) .72
D) .053
E) .026
18) The density of nitric oxide (NO) gas at 1.21 atm and 46.2°C is __________ g/L.
A) 0.0462
B) 0.722
C) 1.39
D) 0.319
E) 9.6
19) 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
20) 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
21) A 1.44-g sample of an unknown pure gas occupies a volume of 0.335 L at a pressure of 1.00 atm and a temperature of 100.0°C. The unknown gas is __________.
A) argon
B) helium
C) krypton
D) neon
E) xenon
22) 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
23) Given the equation:
C2H6 (g) + O2 (g) → CO2 (g) + H2O (g) (not balanced)
Determine the number of liters of CO2 formed at STP. when 240.0 grams of C2H6 is burned in excess oxygen gas.
24) Given the equation:
C2H6 (g) + O2 (g) → CO2 (g) + H2O (g) (not balanced)
Determine the number of liters of O2 consumed at STP when 270.0 grams of C2H6 is burned.
25) 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
26) Zinc reacts with aqueous sulfuric acid to form hydrogen gas:
Zn (s) + H2SO4 (aq) → ZnSO4 (aq) + H2 (g)
In an experiment, 201 mL of wet H2 is collected over water at 27°C and a barometric pressure of 733 torr. The vapor pressure of water at 27°C is 26.74 torr. The partial pressure of hydrogen in this experiment is __________ atm.
A) 0.929
B) 706
C) 0.964
D) 760
E) 1.00
10.4 Short Answer Questions
1) Abnormally high blood pressure is called __________.
2) The temperature and pressure specified by STP are __________ °C and __________ atm.
3) How many molecules are there in 4.00 L of oxygen gas at 500 °C and 50.0 torr?
4) The volume of HCl gas required to react with excess Ca to produce 11.4 L of hydrogen gas at 1.62 atm and 62.0°C is __________ L.
5) What is the density (in g/L) of oxygen gas at 77.0°C and 700.0 torr?
6) What is the partial pressure (in mm Hg) of neon in a 4.00 L vessel that contains 0.838 mol of methane, 0.184 mol of ethane, and 0.755 mol of neon at a total pressure of 928 mm Hg?
7) The rms speed of methane molecules at 45.0°C is __________ m/sec.
8) The deviation from ideal behavior of a gas is most evident at __________ and/or low temperature.
9) The van der Waals equation corrects the ideal gas law for the finite volume and __________ of gas molecules.
10.5 True/False Questions
1) The main component of air is oxygen.
2) If the temperature is lowered from 60°C to 30°C, the volume of a fixed amount of gas will be one half the original volume.
3) A gas is considered “ideal” if one mole of it in a one-liter container exerts a pressure of exactly 1 atm at room temperature.
4) Kinetic-molecular theory assumes that attractive and repulsive forces between gas particles are stronger than those between gas particles and container walls.
5) According to the kinetic-molecular theory, molecules of different gases at the same temperature always have the same average kinetic energy.
6) The effusion rate of a gas is proportional to the square root of its molar mass.
7) Two deviations of real gases from ideal gases which are treated in the van der Waals equation are finite molecular volume and non-zero molecular attractions.
Answer:
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