Deck 8: Gases

Question 1

"The volume of an ideal gas is directly proportional to its absolute temperature at constant pressure and number of moles" is a statement of ________________ law.

A)Charles's
B)Boyle's
C)Dalton's
D)Avogadro's
E)Gay-Lussac's

Answer 1

Charles's

Question 2

A sample of carbon dioxide gas at 125°C and 248 torr occupies a volume of 275 L.What will the gas pressure be if the volume is increased to 321 L at 125°C?

A)212 torr
B)289 torr
C)356 torr
D)441 torr
E)359 torr

Answer 2

212 torr

Question 3

The air pressure in a volleyball is 75 psi.What is this pressure in torr? (1 atm = 14.7 psi = 101,325 Pa = 760 torr)?

A)520 torr
B)562 torr
C)3900 torr
D)7600 torr
E)75,000 torr

Answer 3

3900 torr

Question 4

The pressure of sulfur dioxide in a container is 159 kPa.What is this pressure in atmospheres? (1 atm = 101,325 Pa = 760 torr)?

A)0.209 atm
B)0.637 atm
C)1.57 atm
D)21.2 atm
E)1.59×10⁴ atm

Question 5

Which figure best represents the concept of pressure? (A sphere represents a gaseous atom.)

A)
B)
C)
D)

Question 6

A sample of nitrogen gas at 298 K and 745 torr has a volume of 37.42 L.What volume will it occupy if the pressure is increased to 894 torr at constant temperature?

A)22.3 L
B)31.2 L
C)44.9 L
D)112 L
E)380 L

Question 7

Which is not a property of a gas?

A)The density of a gaseous substance varies strongly with temperature.
B)A sample of gas assumes the shape and volume of its container.
C)Gases are highly compressible.
D)The densities of gases are much larger than those of corresponding liquids.
E)Gases form homogeneous mixtures with one another in any proportion.

Question 8

A sample of a gas has an initial pressure of 0.987 atm and a volume of 12.8 L.What is the final pressure if the volume is increased to 25.6 L?

A)2.03 atm
B)1.97 atm
C)0.494 atm
D)0.003 atm
E)323.4 atm

Question 9

The pressure of hydrogen sulfide gas in a container is 3.565 ×10⁴ Pa.What is this pressure in torr? (1 atm = 101,325 Pa = 760 torr)?

A)46.91 torr
B)267.4 torr
C)351.8 torr
D)3612 torr
E)2.709 ×10⁴ torr

Question 10

If the atmospheric pressure in Denver is 0.8800 atm, what is this pressure expressed in mmHg? (1 atm = 101,325 Pa = 760 torr, 1 torr = 1 mmHg)?

A)151.5 mmHg
B)1.16× 10⁻³ mmHg
C)863.6 mmHg
D)8.92 × 10⁴ mmHg
E)668.8 mmHg

Question 11

A sample of a gas occupies 1.40 L at 25°C and 760 mmHg.What volume will it occupy at the same temperature and 380 mmHg?

A)2.8 L
B)2.10 L
C)1.40 L
D)1.05 L
E)0.700 L

Question 12

Which represents the definition of pressure?

A)volume/density
B)temperature × area
C)moles/volume
D)force/area
E)volume × force

Question 13

A sample of nitrogen gas has a volume of 32.4 L at 20°C.The gas is heated to 220ºC at constant pressure.What is the final volume of the nitrogen gas?

A)2.94 L
B)19.3 L
C)32.4 L
D)54.5 L
E)356 L

Question 14

A sample of hydrogen gas exerts a pressure of 466 torr in a container.What is this pressure in atmospheres? (1 atm = 1.01325 ×10⁵ Pa = 760 torr)

A)0.217 atm
B)0.466 atm
C)0.613 atm
D)1.63 atm
E)4.60 atm

Question 15

What are the conditions of STP?

A)0 K and 1 atm
B)273.15 K and 760 torr
C)0°C and 760 atm
D)273.15°C and 760 torr
E)0°C and 1 torr

Question 16

"The pressure of an ideal gas is inversely proportional to its volume at constant temperature and number of moles" is a statement of __________________ law.

A)Charles's
B)Boyle's
C)Amontons's
D)Avogadro's
E)Gay-Lussac's

Question 17

Which of the following is/are characteristic(s) of gases?

A)High compressibility
B)Relatively large distances between molecules
C)Formation of homogeneous mixtures regardless of the nature of gases
D)Choice 1 and 2 only
E)Choice 1, 2, and 3

Question 18

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of _____________ law.

A)Charles's
B)Boyle's
C)Dalton's
D)Avogadro's
E)Gay-Lussac's

Question 19

A sample of gas occupies 24.5 L at a pressure of 1.57 atm.What is the pressure if the volume is increased to 48.3 L at constant temperature?

A)0.796 atm
B)1.26 atm
C)3.10 atm
D)5.38 × 10⁻⁴ atm
E)1.86 × 10³ atm

Question 20

Which of the following is not a gas at room temperature and pressure?

A)NH₃
B)CO₂
C)I₂
D)CH₄
E)H₂

Question 21

If 25.5 L of oxygen are cooled from 150^°C to 50^°C at constant pressure, what is the new volume of oxygen?

A)0.0514 L
B)19.5 L
C)33.4 L
D)0.03 L
E)3.5 L

Question 22

What is the formula which describes the relationship between the pressure, volume, temperature, and moles?

A)
B)
C)
D)

Question 23

What is the volume occupied by 25.2 g of CO₂ at 0.840 atm and 25°C? (R = 0.08206 L • atm/K • mol)

A)0.060 L
B)1.34 L
C)16.7 L
D)24.2 L
E)734 L

Question 24

What is the final temperature of a gas that expands from a volume of 22.4 L at 278 K to a volume of 38.3 L?

A)163 K
B)294 K
C)3.09 K
D)217 K
E)475 K

Question 25

A sample of propane, a component of LP gas, has a volume of 35.3 L at 315 K and 922 torr.What is its volume at STP? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

A)25.2 L
B)30.6 L
C)33.6 L
D)37.1 L
E)49.2 L

Question 26

A sample of N₂ gas occupies 2.40 L at 20°C.At what temperature will the N₂ gas occupy a volume of 4.80 L at constant pressure?

A)10°C
B)40°C
C)146°C
D)313°C
E)586°C

Question 27

If 2.3 mol of a gas occupies 50.5 mL, how many moles of the gas will occupy 85.5 mL at the same temperature and pressure?

A)1.4 mol
B)0.59 mol
C)3.9 mol
D)0.26 mol
E)2.3 mol

Question 28

A gas cylinder containing 1.50 mol compressed methane has a volume of 3.30 L.What pressure does the methane exert on the walls of the cylinder if its temperature is 25°C? (R = 0.08206 L • atm/K • mol)

A)9.00 × 10⁻² atm
B)0.933 atm
C)1.11 atm
D)1.70 atm
E)11.1 atm

Question 29

A sample of nitrogen gas is confined to a 14.0-L container at 375 torr and 37.0°C.How many moles of nitrogen are in the container? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

A)0.272 mol
B)2.27 mol
C)3.69 mol
D)206 mol
E)227 mol

Question 30

A sample of an ideal gas has its volume doubled while its temperature remains constant.If the original pressure was 100 torr, what is the new pressure?

A)10 torr
B)50 torr
C)100 torr
D)200 torr
E)1000 torr

Question 31

What is the mass, in grams, of 2.74 L of CO gas measured at 33°C and 945 mmHg? (R = 0.08206 L • atm/mol • K, 1 atm = 760 mmHg)

A)0.263 g
B)2.46 g
C)3.80 g
D)35.2 g
E)206 g

Question 32

A fixed quantity of gas has a pressure of 1.35 atm, a volume of 23.8 L, and a temperature of 205.1 K.If the pressure increases to 2.84 atm and the temperature rises to 233.4 K, what is the new volume of the gas?

A)0.183 L
B)7.06 L
C)9.94 L
D)12.9 L
E)57.0 L

Question 33

If a fixed amount of a gas is at a pressure of 2.71 atm and has a volume of 85.3 L at a temperature of 173.4 K, what is the final temperature of the gas if the pressure changes to 1.04 atm in a 105.3 L container?

A)49.8 K
B)75.9 K
C)366.0 K
D)82.1 K
E)557.8 K

Question 34

A gas sample occupies 8.76 L at a temperature of 37°C.What is the volume if the temperature is lowered to 0°C at constant pressure?

A)9.95 L
B)0 L
C)4.22 L
D)74.1 L
E)7.71 L

Question 35

How many molecules of N₂ gas are present in a 2.5-L flask at 50°C and 650 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg, 1 mole = 6.022 × 10²³ molecules)

A)2.1 × 10⁻²³ molecules
B)4.9 × 10²² molecules
C)3.1 × 10²³ molecules
D)3.6 × 10²⁵ molecules
E)0.081 molecules

Question 36

A sample of nitrogen gas has the temperature drop from 250.°C to 150.°C at constant pressure.What is the final volume if the initial volume is 310.mL?

A)0.186 L
B)0.251 L
C)0.383 L
D)0.410 L
E)0.517 L

Question 37

A gas evolved during the fermentation of sugar was collected at 22.5°C and 702 mmHg.After purification its volume was found to be 25.0 L.How many moles of gas were collected? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

A)0.952 mol
B)1.05 mol
C)12.5 mol
D)22.4 mol
E)724 mol

Question 38

If 2.38 mol of a gas has a volume of 120.0 mL, what is the volume of 1.97 mol of the gas at the same temperature and pressure?

A)25.6 mL
B)99.3 mL
C)119 mL
D)145 mL
E)563 mL

Question 39

What is the volume occupied by 35.2 g of methane gas (CH₄) at 25°C and 1.0 atm? (R = 0.08206 L • atm/K • mol)

A)0.0186 L
B)4.5 L
C)11.2 L
D)49.2 L
E)53.7 L

Question 40

What is the initial pressure of a gas having an initial temperature of 905 K, an initial volume of 14.3 L, a final pressure of 0.83 atm, a final temperature of 154 K and a final volume of 2.7 L?

A)26 atm
B)0.27 atm
C)0.75 atm
D)1.3 atm
E)0.92 atm

Question 41

A 7.75-L flask contains 0.482 g of hydrogen gas and 4.98 g of oxygen gas at 65°C.What is the partial pressure of oxygen in the flask?

A)0.557 atm
B)0.043 atm
C)1.11 atm
D)33.5 atm
E)67 atm

Question 42

A 0.271-g sample of an unknown vapor occupies 294 mL at 140°C and 847 mmHg.The empirical formula of the compound is CH₂.What is the molecular formula of the compound? (R = 0.08206 L • atm/K • mol)

A)CH₂
B)C₂H₄
C)C₃H₆
D)C₄H₈
E)C₆H₁₂

Question 43

What is the density of Ar(g) at −11°C and 675 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

A)1.52 g/L
B)1.65 g/L
C)−39.3 g/L
D)40.0 g/L
E)1.25 kg/L

Question 44

Gases are sold in large cylinders for laboratory use.What pressure is exerted by 2.500 kg of oxygen gas (O₂) stored at 22°C in a 40.0-L cylinder? (R = 0.08206 L • atm/K • mol)

A)3.55 atm
B)1.51 ×10³ atm
C)47.3 atm
D)7.56 × 10⁴ atm
E)10.2 atm

Question 45

A 250.0-mL sample of ammonia, NH₃(g), exerts a pressure of 833 torr at 42.4°C.What mass of ammonia is in the container? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

A)0.0787 g
B)0.180 g
C)8.04 g
D)17.0 g
E)59.8 g

Question 46

What is the density of carbon dioxide gas at −25.2°C and 98.0 kPa? (R = 0.08206 L • atm/K • mol, 1 atm = 101,325 Pa)

A)0.232 g/L
B)0.279 g/L
C)0.994 g/L
D)1.74 g/L
E)2.09 g/L

Question 47

What is the molar mass of an unknown gas if a sample weighing 0.389 g is collected in a flask with a volume of 102 cm³ at 97°C and at a pressure of 728 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg).

A)187 g/mol
B)121 g/mol
C)112 g/mol
D)31.6 g/mol
E)8.28 × 10⁻³ g/mol

Question 48

Determine the partial pressure of helium in a gas mixture composed of 10.0 grams of CO₂ and 10.0 grams of helium.The mixture is at 75ºC in a 12.0-liter container.

A)5.95 atm
B)1.28 atm
C)0.541 atm
D)0.117 atm
E)7.23 atm

Question 49

Determine the mole fraction of CO₂ in a gas mixture composed of 10.0 grams of CO₂ and 10.0 grams of helium.The mixture is at 75ºC in a 12.0-liter container.

A)0.92
B)2.7
C)0.23
D)0.080
E)0.77

Question 50

Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100 cm³ at 95°C and 1000 mmHg (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg).

A)0.19 g/mol
B)35.3 g/mol
C)70.9 g/mol
D)137 g/mol
E)384 g/mol

Question 51

A block of dry ice (solid CO₂, density = 1.56 g/mL) of dimensions 25.0 cm × 25.0 cm × 25.0 cm is left to sublime (i.e., to pass from the solid phase to the gas phase) in a closed chamber of dimensions 4.00 m × 5.00 m × 3.00 m.Once the sublimation is complete, what is the partial pressure of carbon dioxide in the chamber at 25°C? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

A)172 mmHg
B)107 mmHg
C)0.225 mmHg
D)0.172 mmHg
E)14.4 mmHg

Question 52

A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass.A 5.25-g sample of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at −4.0°C.What is its molecular formula? (R = 0.08206 L • atm/K • mol)

A)NO
B)NO₂
C)N₃O₆
D)N₂O₄
E)N₂O₅

Question 53

What is the density of SF₆(g) at 27°C and 0.500 atm pressure? (R = 0.08206 L • atm/K • mol)

A)3.38 × 10⁻³ g/L
B)2.97 g/L
C)22.4 g/L
D)32.9 g/L
E)3.38 kg/L

Question 54

Determine the mole fraction of CO in a gas mixture composed of 782.4 grams of CO₂ and 2.10 moles of CO.The mixture is at 703.3 K in a 25.8-liter container.

A)0.11
B)0.89
C)17.8
D)0.48
E)0.52

Question 55

Determine the mole fraction of N₂ in a gas mixture composed of 1.0 mol of N₂ and 1.5 mol of Ar.The mixture is at 0.0ºC in a 10.0-liter container.

A)0.40
B)0.60
C)1.0
D)1.5
E)2.5

Question 56

What is the density of CO₂(g) at 100.°C and 10.0 atm pressure? (R = 0.08206 L • atm/K • mol)

A)1.44 g/L
B)134 g/L
C)44.0 g/L
D)53.6 g/L
E)14.4 g/L

Question 57

Determine the partial pressure of CO₂ in a gas mixture composed of 782.4 grams of CO₂ and 2.10 moles of CO.The mixture is at 703.3 K in a 25.8-liter container.

A)4.70 atm
B)44.5 atm
C)39.8 atm
D)22.4 atm
E)17.8 atm

Question 58

Determine the partial pressure of N₂ in a gas mixture composed of 1.0 mol of N₂ and 1.5 mol of Ar.The mixture is at 0.0ºC in a 10.0-liter container.

A)3.36 atm
B)0.00 atm
C)5.60 atm
D)6.12 atm
E)2.24 atm

Question 59

Assuming ideal behavior, what is the density of argon gas at STP? (R = 0.08206 L • atm/K • mol)

A)0.0176 g/L
B)0.0250 g/L
C)0.0561 g/L
D)1.78 g/L
E)181 g/L

Question 60

A flask with a volume of 3.16 L contains 9.33 g of an unknown gas at 32.0°C and 1.00 atm.What is the molar mass of the gas? (R = 0.08206 L • atm/K • mol)

A)7.76 g/mol
B)66.1 g/mol
C)73.9 g/mol
D)81.4 g/mol
E)144 g/mol