Deck 10: Gases

Question 1

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

Answer 1

are all homogeneous

Question 2

Of the following, __________ has a slight odor of bitter almonds and is toxic.

A)NH₃
B)N₂O
C)CO
D)CH₄
E)HCN

Answer 2

HCN

Question 3

Of the following, __________ has the odor of rotting eggs.

A)NH₃
B)H₂S
C)CO
D)NO₂
E)HCN

Answer 3

H₂S

Question 4

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

Question 5

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

Question 6

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

Question 7

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

Question 8

"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

Question 9

Of the following, __________ is a correct statement of Boyle's law.

A)PV = constant
B) = constant
C) = constant
D) = constant
E) = constant

Question 10

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.

Question 11

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

Question 12

The volume of an ideal gas is zero at __________.

A)0 °C
B)-45 °F
C)-273 K
D)-363 K
E)-273 °C

Question 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

Question 14

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

Question 15

Of the following, only __________ is impossible for an ideal gas.

A)
B)V₁T₁ = V₂T₂
C)
D)
E)

Question 16

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.

Question 17

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

Question 18

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.

Question 19

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

Question 20

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

Question 21

The density of __________ is 0.900 g/L at STP.

A)CH₄
B)Ne
C)CO
D)N₂
E)NO

Question 22

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

Question 23

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

Question 24

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

Question 25

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

Question 26

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

Question 27

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

Question 28

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

Question 29

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

Question 30

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

Question 31

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

Question 32

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

Question 33

A sample of an unknown volatile liquid was injected into a Dumas flask (m_flask = 27.0928 g, V_flask = 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 (m_flask+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

Question 34

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

Question 35

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

Question 36

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

Question 37

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

Question 38

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

Question 39

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

Question 40

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

Question 41

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

Question 42

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

Question 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

Question 44

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

Question 45

Which one of the following gases would deviate the least from ideal gas behavior?

A)Ne
B)CH₃Cl
C)Kr
D)CO₂
E)F₂

Question 46

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

Question 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

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

Question 52

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

Question 53

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

Question 54

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

Question 55

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

Question 56

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

Question 57

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.

Question 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

Question 59

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

Question 60

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.

Question 61

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

Question 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

Question 63

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

Question 64

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

Question 65

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

Question 66

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

Question 67

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

Question 68

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

Question 69

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

Question 70

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

Question 71

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

Question 72

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

Question 73

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

Question 74

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

Question 75

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

Question 76

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

Question 77

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

Question 78

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

Question 79

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

Question 80

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