Deck 10: Gases

Question 1

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.

Answer 1

With an increase in altitude, atmospheric pressure increases as well.

Question 2

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

Answer 2

Robert Boyle

Question 3

One significant difference between gases and liquids is that ________.

A)a gas is made up of molecules
B)a gas expands to fill 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.

Answer 3

a gas expands to fill its container

Question 4

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 5

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 × 10⁴ Pa
C)0.760 atm = 578 mm Hg
D)1.0 torr = 2.00 mm Hg
E)1.00 atm = 760 torr

Question 6

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 7

Which of the following is not a unit of pressure?

A)mm Hg
B)mm
C)atm
D)Pa
E)psi

Question 8

Of the following,________ has the odor of rotten eggs.

A)NH₃
B)H₂S
C)CO
D)NO₂
E)HCN

Question 9

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 -Pa/mol-K
C)62.36 L torr mol^-1K^-1
D)1.987 cal mol^-1K^-1
E)none of the above

Question 10

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 11

Of the following,________ has a strong acrid odor.

A)N₂O
B)CH₄
C)CO
D)NH₃
E)HCN

Question 12

"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 ΔH_rxn = 0

Question 13

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, How high a column of methanol would be supported by a pressure that supports a 713 mm column of mercury

A)713 mm
B)41 mm
C)1.2 × 10⁴ mm
D)9.7 × 10³ mm
E)17 mm

Question 14

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

Question 15

The temperature of an ideal gas at STP is ________.

A)0 °C
B)-32 °F
C)-273 K
D)0 °F
E)0 K

Question 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

Question 17

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

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

Question 18

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 19

Which of the following is not possible for an ideal gas?

A) =
B) =
C) =
D) =
E) = = 0

Question 20

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 21

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 22

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 23

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 24

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 25

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 26

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 27

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)B and D

Question 28

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 29

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 30

A sample of an unknown volatile liquid was injected into a Dumas flask and heated until no visible traces of the liquid could be found.The flask and its contents were then rapidly cooled and reweighed 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 31

How much CO₂ (L)is produced when 2.10 kg of sodium bicarbonate reacts with excess hydrochloric acid at 25.0 °C and 1.23 atm?

A)4.17 × 10^-1
B)4.98 × 10²
C)4.17 × 10¹
D)3.50
E)4.98 × 10^-1

Question 32

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 33

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 34

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)ethanol
B)propanol
C)butanol
D)hexanol
E)methanol

Question 35

What is the temperature at STP?

A)0 °C
B)25 °C
C)-32 °F
D)298 k
E)0 k

Question 36

The average kinetic energy of the particles of a gas is ________ proportional to ________.

A)directly, the rms speed
B)directly, the square root of the rms speed
C)inversely, the square of the rms speed
D)directly, the square of the rms speed
E)inversely, the particle mass

Question 37

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 38

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)NH₃
E)HF

Question 39

Which of the following gases would have a similar rate of effusion to CO at 350 K?

A)H₂
B)He
C)CO₂
D)N₂
E)NO₂

Question 40

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 41

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 42

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 43

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 44

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 45

760 torr is equivalent to ________ mm Hg.

A)380
B)4.78 × 10³
C)1
D)760
E)121

Question 46

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 47

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

Question 48

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 49

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 50

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 51

Real gases do not behave ideally at ________.

A)high pressure and low temperature
B)low pressure and high temperature
C)high pressure and high temperature
D)low pressure and low temperature
E)high pressure only

Question 52

Carbon dioxide and an unknown gas start to effuse from a container and the carbon dioxide takes 4.69 times as long to escape as the unknown gas.What is the identity of the unknown gas?

A)(_Br2)
B)NO₂
C)HCl
D)CO
E)H₂

Question 53

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 54

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 55

Two gases start to escape from a container and one of the gases effuses 1.25 times as fast as the other one.The two gases could have been ________.

A)NO and SF₆
B)CO and CO₂
C)CO₂ and Cl₂
D)Cl₂ and CO
E)CO₂ and SF₆

Question 56

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 57

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 58

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 59

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 60

How much faster does ⁷⁹Br₂ effuse than ⁸¹Br₂?

A)0.975 times as fast
B)1.025 times as fast
C)1.013 times as fast
D)0.988 times as fast
E)Cannot be determined

Question 61

What is the molecular weight (g/mol)of an unknown gas that has a density of 3.59 g/L at STP?

A)7.37
B)87.9
C)0.0879
D)80.5
E)8.15 × 10³

Question 62

If pressure and temperature are kept constant,the reaction of 18 mL of N₂ gas with 54 mL of H₂ gas will form ________ mL of ammonia.

A)108
B)18
C)9
D)36
E)27

Question 63

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 64

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

Question 65

If pressure and temperature are kept constant,the reaction of 95 mL of Cl₂ gas with 45 mL of CH₄ gas via the equation: Cl₂ (g)+ CH₄ (g)→ HCl (g)+ CH₃Cl (g)
Will produce a total of ________ mL of products.

A)95
B)140
C)45
D)70
E)50

Question 66

What is the volume (in m³)of a 0.25 mol of an unknown gas at a pressure of 545.3 mm Hg and 15 °C?

A)8.1 × 10^-5
B)18.2 × 10^-3
C)4.3 × 10^-4
D)2.2 × 10^-1
E)1.2 × 10^-4

Question 67

What is the molecular weight (g/mol)of an unknown gas that has a density of 4.90 g/L at STP?

A)1.10 × 10^-2
B)1.20 × 10²
C)1.10 × 10²
D)1.20 × 10^-2
E)1.10

Question 68

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

Question 69

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

Question 70

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

Question 71

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

Question 72

What is the density of (g/L)CO₂ at 1.53 atm and 45.2 °C?

A)18.2
B)2.58
C)0.388
D)9.99
E)1.76

Question 73

How many moles of an unknown gas are in a 325 mL container at a pressure of 695 torr and 19 °C?

A)9.42
B)1.48 × 10^-2
C)12.4
D)1.24 × 10^-2
E)80.6

Question 74

If pressure and temperature are kept constant,the reaction of 29 mL of N₂ gas with 87 mL of H₂ gas will form ________ mL of ammonia.

A)29
B)43.5
C)58
D)174
E)14.5

Question 75

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 76

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

Question 77

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

Question 78

If pressure and temperature are kept constant,the reaction of 38 mL of Cl₂ gas with 22 mL of CH₄ gas via the equation: Cl₂ (g)+ CH₄ (g)→ HCl (g)+ CH₃Cl (g)
Will produce a total of ________ mL of products.

A)16
B)30
C)60
D)38
E)22

Question 79

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

Question 80

What mass (g)of carbon dioxide is contained in a 5.33 L vessel at 48 °C and 1.44 atm?

A)12.8
B)6.62 × 10^-3
C)0.291
D)44.0
E)151