Deck 6: Gases

Question 1

The statement, "For a fixed mass of gas at constant temperature, gas volume is inversely proportional to gas pressure" is known as Charles' Law .

Answer 1

False

Question 2

2.24 L NH3(g) at 2.0 atm and 0°C:

A) contains 0.050 mole NH3
B) weighs 1.70 g
C) contains 6.02 × 1022 molecules of NH3
D) contains 3.6 × 1023 H atoms
E) contains 3.6 × 1023 N atoms

Answer 2

contains 3.6 × 1023 H atoms

Question 3

According to the kinetic-molecular theory of gases, at constant temperature, all particles have equal translational kinetic energy.

Answer 3

False

Question 4

Liquid mercury freezes at a temperature of -39°C. The freezing point of mercury on the Kelvin scale is 234 K

Question 5

The ideal gas equation connects three basic variables: volume, amount, and temperature of a gas.

Question 6

The relationship between the "absolute temperature" on the Kelvin scale and the Celsius temperature is given by:

A) T(K) = t(°C) + 273.15
B) t(°C) = T(K) + 273.15
C) T(K) = 5/8[t(°C)] - 32
D) T(K) = 8/5[t(°C)] + 32
E) t(°C) = 98.6 + T(K)

Question 7

Convert to the equivalent pressure in atmospheres, 4.32 × 105 N/m2.

A) 4.26 atm
B) 4.38 × 1010 atm
C) 4.26 × 103 atm
D) 3.31 × 105 atm
E) 0.235 atm

Question 8

To increase the volume of a fixed amount of gas from 100 cm3 to 200 cm3:

A) increase the temperature from 25.0 to 50.0°C at constant pressure
B) increase the pressure from 1.00 to 2.00 atm at constant temperature
C) reduce the temperature from 400 K to 200 K at constant pressure
D) reduce the pressure from 608 mm Hg to 0.40 atm at constant temperature
E) decrease the temperature from 600 K to 400 K

Question 9

The mutual attraction of gas molecules is an important aspect of van der Waals' equation.

Question 10

If someone were to light a cigar at one end of a closed room, persons at the other end of the room might soon perceive an odor due to gaseous emissions from the cigar. Such a phenomenon is an example of effusion.

Question 11

A gaseous mixture consists of 50.0% O₂, 25.0% N₂, and 25.0% Cl₂, by mass. At standard temperature and pressure, the partial pressure of N₂(g) is equal to 0.20 atm.

Question 12

Two containers are connected by an open tube. One container (A) is at 300 K, the other (B) is at 600 K. These two containers must have:

A) equal number of moles
B) greater pressure in A than B
C) greater pressure in B than A
D) equal volume
E) none of these

Question 13

The statement, "For a fixed mass of gas at constant temperature, gas volume is inversely proportional to gas pressure." is known as:

A) Avogadro's Law
B) Boyle's Law
C) Charles' Law
D) Graham's Law
E) Kelvin's Law

Question 14

If gas volume is doubled but the temperature remains constant:

A) the pressure stays the same
B) the molecules move faster
C) the final pressure is twice the pressure before the volume change.
D) the molecules move slower
E) the final pressure is 1/2 of the pressure before the volume change.

Question 15

Of the following values, the most likely to be observed for the volume of 1.00 mole of He(g) at 0°C and 1000 atm is:

A) 17.4 mL
B) 46 mL
C) 22.4 mL
D) 11.2 mL
E) 22.4 L

Question 16

Assuming ideal gas behavior, which of the following gases would have the lowest density at standard temperature and pressure?

A) SF6
B) CF2Cl2
C) CO2
D) N2
E) Kr

Question 17

Gas densities depend strongly on gas temperature and pressure.

Question 18

Convert 8.50 kg/cm2 to the equivalent pressure in atmospheres.

A) 8.78 atm
B) 1.12 atm
C) 9.53 atm
D) 8.23 atm
E) 7.47 atm

Question 19

Pressure is a force per unit area with the SI unit of 1 pascal

Question 20

The relationship between the "absolute temperature" on the Kelvin scale and the Celsius temperature is given by T(K) = 5/8[t(°C)] - 32

Question 21

If a liter of CO2 is compared to a liter of H2, both at 25°C and one atmosphere pressure, then:

A) the CO2 and H2 molecules have the same average speed
B) there are more H2 molecules than CO2 molecules
C) the average kinetic energy of the CO2 molecules is greater than that of the H2 molecules
D) the CO2 molecules are, on the average, moving more slowly than the H2 molecules
E) the mass of one liter of CO2 equals the mass of one liter of H2

Question 22

Of the following gases, the one with the greatest density at STP is:

A) CH4
B) NH3
C) Ne
D) H2
E) He

Question 23

The energy of molecules of a gas:

A) is dependent on concentration
B) is distributed over a wide range at constant temperature
C) is the same for all molecules at constant temperature
D) increases with a decrease in temperature
E) increases with an increase in pressure

Question 24

A gaseous mixture consists of 50.0% O2, 25.0% N2, and 25.0% Cl2, by mass. At standard temperature and pressure, the partial pressure of:

A) Cl2(g) is greater than 0.25 atm
B) O2(g) is equal to 380 torr
C) Cl2(g) is less than 0.25 atm
D) N2(g) is equal to 0.20 atm
E) O2(g) is equal to 1.6 atm

Question 25

What volume would be occupied by 4.8 g of oxygen gas at 0.50 atm and 133°C?

A) 19 L
B) 13 L
C) 10 L
D) 6.7 L
E) 3.3 L

Question 26

53.5 g of an ideal gas of molecular weight = 30.5 g/mol is confined at a pressure of 133 mmHg. The density of the gas is 0.228 g/L. Compute the temperature of the gas in degrees Celsius.

A) 261°C
B) 12.°C
C) -57°C
D) 285°C
E) -12.°C

Question 27

If 0.50 mole H2(g) and 1.0 mole He(g) are compared at standard temperature and pressure, the two gases will:

A) have equal effusion rates
B) have equal average molecular velocities
C) have equal average molecular kinetic energies
D) occupy equal volumes
E) have equal weights

Question 28

In the reaction Fe2O3 + 3 H2 → 2 Fe + 3 H2O, how many moles of iron can be produced using 17.4 liters of hydrogen at STP?

A) (17.4/22.4)(2/3) mol
B) (17.4/22.4)(3/2) mol
C) (17.4)(2/3) mol
D) (17.4/22.4) mol
E) (17.4)(22.4/3) mol

Question 29

At 27°C and 750 torr, both a 16 g sample of methane gas (CH4) and a 16 g sample of oxygen gas (O2) will have the same:

A) average molecular velocities
B) average molecular kinetic energies
C) number of gaseous particles
D) total gaseous volumes
E) average effusion rates

Question 30

When one volume of CO reacts with one volume of Cl2 phosgene is obtained as the only product. What is empirical formula of phosgene?

A) COCl2
B) C2O2Cl2
C) C2O2Cl
D) C3O3Cl2
E) COCl4

Question 31

Which of the following is a characteristic of an ideal gas?

A) Gas cannot be compressed infinitely.
B) Inter-particle forces are prominent.
C) Collisions between gas particles are perfectly elastic
D) Collisions between gas particles and container walls are not elastic
E) Individual gas particles occupy fixed volume.

Question 32

In the reaction 2 Na + 2 H2O → 2 NaOH + H2, how many liters of hydrogen at STP are produced from 50.0 grams of sodium (Na = 23.0, O = 16.0, H = 1.0 g/mol)?

A) (55.0/18.0)(22.4) L
B) (50.0/23.0)(22.4/2) L
C) (50.0/23.0)(2)(22.4) L
D) (50.0/23.0)(22.4) L
E) (55.0/23.0)(22.4) L

Question 33

A balloon with volume 750 cm3 is filled with O2 at 27°C has a mass of 83.3 g. The mass of empty balloon is 82.1 g. Calculate the pressure of O2.

A) 125 kPa
B) 150 kPa
C) 250 kPa
D) 75 kPa
E) 400 kPa

Question 34

In the reaction: 2 Al(s) + 6 HCl(aq) → 2 AlCl3(aq) + 3 H2(g)

A) 67.2 L of H2(g) at STP is collected for every mole of Al reacted
B) 33.6 L of H2(g) is collected for every mole of Al reacted, regardless of the temperature and pressure
C) 1.24 cm3 H2(g) at STP is collected for every milligram of Al reacted
D) 6 L HCl(aq) is consumed for every 3 L H2(g) produced
E) 22.4 L of H2(g) is produced for every mole of Al reacted

Question 35

Three volumes of O2 and one volume of CH4 are placed in a sealed container. The temperature and pressure of this mixture are 120°C and 600 kPa. What is the pressure in the same container after the explosion of the mixture and after it was cooled to the initial temperature?

A) 350 kPa
B) 600 kPa
C) 950 kPa
D) 750 kPa
E) 575 kPa

Question 36

The addition of 2.0 g He(g) to a vessel of 10.0 L fixed volume already containing O2(g) at 25°C and 740 mmHg will:

A) have no effect on the final gas pressure
B) cause the final pressure to exceed 2 atm
C) produce a 20% increase in gas pressure
D) bring the final pressure to just slightly more than 1 atm
E) cause the final pressure to exceed 4 atm

Question 37

What volume of acetylene gas, C2H2, would be required at 0°C and 1 atm to obtain a 200.0 g C2H2 sample?

A) 4480 L
B) 1.309 × 105 L
C) 320.0 L
D) 0.6304 L
E) 172.1 L

Question 38

Subtracting the vapor pressure of water from the total pressure of a gas collected over water is an example of the application of:

A) Avogadro's Hypothesis
B) Dalton's Law
C) Graham's Law
D) van der Waals Theory
E) ideal gas law

Question 39

According to the kinetic-molecular theory of gases:

A) gaseous particles are in constant, nonlinear motion
B) at constant temperature, all particles have equal translational kinetic energy
C) the faster a given particle is moving, the greater its translational kinetic energy
D) at constant temperature, average kinetic energy is a function of gas volume
E) all interparticle collisions are completely inelastic

Question 40

Calculate urms, in m/s, for H2(g) molecules at 30°C.

A) 6.09 × 102 m/s
B) 5.26 × 103 m/s
C) 6.12 × 101 m/s
D) 1.94 × 103 m/s
E) 2.74 × 103 m/s

Question 41

A sample of gas has a volume of 2.5 L at 30°C and 720 mmHg. What will be the volume of this gas at 22°C and 750 mmHg?

A) 1.8 L
B) 3.3 L
C) 2.7 L
D) 2.3 L
E) 2.5 L

Question 42

Calculate the height in meters of a column of liquid glycerol (density = 1.26 g/cm3) required to exert the same pressure as 760 mmHg (d = 13.60 g/cm3).

A) 8.20 m
B) 8.20 × 103 m
C) 70.4 m
D) 0.704 m
E) 44.4 m

Question 43

Convert to the equivalent pressure in atmospheres, 421 kPa.

A) 4.27 × 105 atm
B) 320 atm
C) 0.554 atm
D) 0.00415 atm
E) 4.15 atm

Question 44

A 4.0 L sample of N2(g) at 760 mmHg is compressed, at constant temperature, to 3.2 atm. What is the final gas volume?

A) 950 L
B) 13 L
C) 59 L
D) 1.3 L
E) 0.77 L

Question 45

Calculate the height of a column of liquid glycerol (d = 1.26 g/cm3), in meters, required to exert the same pressure as 4.91 m of water.

A) 4.91 m
B) 3.90 m
C) 6.19 m
D) 3.65 m
E) 5.16 m

Question 46

The mutual attraction of gas molecules is an important aspect of:

A) Avogadro's Hypothesis
B) Dalton's Law
C) Graham's Law
D) van der Waals Theory
E) ideal gas law

Question 47

Liquid mercury freezes at a temperature of -39 °C. The freezing point of mercury on the Kelvin scale is ________.

A) 234 K
B) 39 K
C) 312 K
D) 273 K
E) -39 K

Question 48

Convert to the equivalent pressure in atmospheres, 780 torr.

A) 0.974 atm
B) 1.03 atm
C) 20 atm
D) 5.93 × 105 atm
E) 5.85 atm

Question 49

Gases tend to behave ideally at:

A) low temperature and low pressure
B) low temperature and high pressure
C) high temperature and low pressure
D) high temperature and high pressure
E) gases always behave ideally

Question 50

If someone were to light a cigar at one end of a closed room, persons at the other end of the room might soon perceive an odor due to gaseous emissions from the cigar. Such a phenomenon is an example of:

A) monometry
B) ideality
C) effusion
D) diffusion
E) barometry

Question 51

If 4.800 × 10-5 mol of uranium-238 will effuse through a hole in 125 seconds, how many mol of uranium-235 will effuse through the same hole in the same amount of time?

A) 4.74 × 10-5 mol
B) 4.77 × 10-5 mol
C) 4.80 × 10-5 mol
D) 4.86 × 10-5 mol
E) 4.83 × 10-5 mol

Question 52

A 40.2 L constant-volume cylinder containing 2.21 mol He is heated until the pressure reaches 4.20 atm. What is the final temperature?

A) 258 K
B) 658 K
C) 931 K
D) 804 K
E) 1074 K

Question 53

Convert to the equivalent pressure in atmospheres, 1250 mmHg.

A) 9.50 × 105 atm
B) 490 atm
C) 1.64 atm
D) 0.608 atm
E) 1.22 atm

Question 54

A sample of helium gas occupies a volume of 38 L at 780 torr and 25°C. What volume would the gas occupy at 0°C and 1 atm?

A) 40 L
B) 38 L
C) 36 L
D) 34 L
E) 25 L

Question 55

The fact that a balloon filled with helium will leak more slowly than one filled with hydrogen is explained by citing:

A) Avogadro's Hypothesis
B) Dalton's Law
C) Graham's Law
D) van der Waals Theory
E) ideal gas law

Question 56

Under conditions for which chlorine gas has an effusion rate of 2.4 × 10-6 mol/sec, what would be the effusion rate for bromine gas, in mol/sec?

A) 1.1 × 10-6 mol/sec
B) 1.6 × 10-6 mol/sec
C) 2.3 × 10-6 mol/sec
D) 3.6 × 10-6 mol/sec
E) 5.4 × 10-6 mol/sec

Question 57

The volume correction term in the van der Waals equation is present because:

A) barometers are inaccurate
B) molecules are diatomic
C) molecules attract each other
D) molecules occupy volume
E) molecules repel each other

Question 58

Calculate the height in meters of a column of liquid ethanol (density = 0.7893 g/cm3) required to exert the same pressure as 760 mmHg (d = 13.60 g/cm3).

A) 1.31 × 104 m
B) 13.1 m
C) 70.8 m
D) 0.0708 m
E) 44.1 m

Question 59

A 50.0 mL canister of Freon-12 (CF2Cl2) was heated in boiling water (100.0°C) until the canister burst. If the canister was not defective, and had a burst rating of 103.4 bar, what minimum amount of Freon-12 was in the canister, assuming no volume change before bursting?

A) 9.63 g
B) 11.5 g
C) 20.0 g
D) 27.5 g
E) 75.0 g

Question 60

In which of the following cases is the gas most likely to behave as an ideal gas?

A) H2O(g), 375 K, 750 torr
B) He(g), 37.5 K, 7500 torr
C) CH4(g), 37.5°C, 7.5 atm
D) Ne(g), 375°C, 0.75 atm
E) SF6, -37.5°C, 0.75 atm

Question 61

How many liters of gas is 10.8 grams of nitrogen at 780 mmHg and 38.0°C?

A) 10.1 L
B) 1.17 L
C) 9.59 L
D) 269 L
E) 0.353 L

Question 62

A 10.0 L container of unknown gas at 25.0°C contains 87.1 g of gas at 12.5 atm. What gas is in the container?

A) NH3
B) C2H2
C) SO2
D) F2
E) NO2

Question 63

Diethyl ether (CH3CH2OCH2CH3) was the first general anesthetic. It was first used in 1846 for surgical procedures. What is the density in g/L of diethyl ether at 27°C and 1.11 atm?

A) 37.1 g/L
B) 2.03 × 103 g/L
C) 2.71 g/L
D) 3.34 g/L
E) 0.299 g/L

Question 64

Halothane (CHBrClCF3) is one of the modern anesthetics that is nonflammable and relatively safe for patients. What is the density of halothane in grams per liter at 22°C and 805 torr?

A) 8.63 g/L
B) 7.68 g/L
C) 6.55 × 103 g/L
D) 19.3 g/L
E) 0.130 g/L

Question 65

Diethyl ether was the first general anesthetic. It was first used in 1846 for surgical procedures. What is the molar mass of diethyl ether if 3.54 grams is 1.06 liters at 27°C and 1.11 atm?

A) 74.1 g/mol
B) 6.67 g/mol
C) 103 g/mol
D) 91.3 g/mol
E) 84.7 g/mol

Question 66

What pressure must be applied to N2(g) to obtain a density of 2.00 g/L at 25°C?

A) 1.75 atm
B) 0.146 atm
C) 111 atm
D) 3.49 atm
E) 2.29 atm

Question 67

Butane (C4H10) is used as a fuel where natural gas is not available. How many grams of butane will fill a 3.50 liter container at 35.6°C and 758 torr?

A) 0.138 g
B) 69.5 g
C) 422 g
D) 8.01 g
E) 0.0105 g

Question 68

Chloroform became popular as an anesthetic after Queen Victoria delivered her eighth child while anesthetized by chloroform in 1853. What is the molar mass of chloroform if 4.85 grams is 0.918 liters at 35°C and 850 torr?

A) 149 g/mol
B) 119 g/mol
C) 123 g/mol
D) 134 g/mol
E) 110 g/mol

Question 69

Halothane is one of the modern anesthetics which is nonflammable and relatively safe for patients. What is the molar mass of halothane if 456 milligrams is 52.8 milliliters at 22°C and 805 torr?

A) 1.06 × 103 g/mol
B) 209 g/mol
C) 197 g/mol
D) 221 g/mol
E) 14.7 g/mol

Question 70

How many liters of gas is 23.4 grams of nitrogen at 750 mmHg and 28.0°C?

A) 586 L
B) 20.9 L
C) 0.771 L
D) 20.4 L
E) 1.94 L

Question 71

What mass of water vapor would occupy a volume of 54 L at 200°C and 76 torr, assuming ideal behavior?

A) 1.8 g
B) 2.5 g
C) 4.3 g
D) 5.4 g
E) 7.2 g

Question 72

A gaseous hydrocarbon weighing 0.290 g occupies a volume of 125 mL at 25°C and 760 mmHg. What is the molar mass of this compound?

A) 113 g/mol
B) 4.76 × 103 g/mol
C) 43.1 g/mol
D) 10.5 g/mol
E) 56.7 g/mol

Question 73

Chloroform (CHCl3) became popular as an anesthetic after Queen Victoria delivered her eighth child while anesthetized by chloroform in 1853. What is the density in grams per liter of chloroform at 35°Cand 850 torr?

A) 4.21 g/L
B) 0.190 g/L
C) 2.14 g/L
D) 4.00 × 103 g/L
E) 5.28 g/L

Question 74

A sample of gas weighs 0.250 g and occupies a volume of 112 cm3 at 0 °C and 1 atm. The molecular weight of this gas is ________.

A) 25.0 g/mol
B) 50.0 g/mol
C) 2.23 g/mol
D) 8.0 g/mol
E) 200 g/mol

Question 75

An automobile tire at 32.0 psi at 25.0°C is driven on a trip. At the end of the trip the pressure is 35.0 psi. What is the temperature of the tire in degrees Celsius?

A) 27.3 °C
B) 22.8 °C
C) 52.9 °C
D) 57.0 °C
E) 60.0 °C

Question 76

Calculate the volume of H2(g) expressed at STP, required to react with 3.00 L of CO(g) at STP in the following reaction: 3 CO(g) + 7 H2(g) → C3H8(g) + 3 H2O(l)

A) 3.00 L
B) 7.00 L
C) 10.0 L
D) 22.4 L
E) 1.00 L

Question 77

What is the density of carbon dioxide gas at -15°C and 728 torr?

A) 2.17 g L-1
B) 2.08 g L-1
C) 1.99 g L-1
D) 1.84 g L-1
E) 1.27 g L-1

Question 78

Butane (C4H10) is used as a fuel where natural gas is not available. How many grams of butane will fill a 45.0 liter container at 27°C and 3.05 atm?

A) 26.6 g
B) 3.60 × 103 g
C) 5.58 g
D) 10.4 g
E) 324 g

Question 79

A 5.00 L container of unknown gas at 25.0°C has a pressure of 2.45 atm. The mass of the gas is 32.1 g. What gas is in the container?

A) Cl2
B) F2
C) NO2
D) SO3
E) SO2

Question 80

A 500.0 mL sample of O2(g) is at 780 mmHg and 30°C. What will be the new volume if, with constant pressure and amount of gas, the temperature is decreased to -15°C?

A) 587 mL
B) 250 mL
C) 437 mL
D) 426 mL
E) 500 mL