Deck 11: Properties of Gases

Question 1

A special shipping container for compressed gas is rated at 18.50 × 10³ kPa. What is this rating in kbar?(1 atm = 101325 Pa = 760 torr = 760 mm Hg = 1.01325 bar = 1013.25 mb)

A)14.06 kbar
B)180.2 kbar
C)18.02 kbar
D)0.1850 kbar
E)18.50 kbar

Answer 1

0.1850 kbar

Question 2

A closed-end manometer was constructed from a U-shaped glass tube. It was loaded with mercury so that the closed side was filled all the way to the top, which was 800 mm above the neck, while the open end was at a level 180 mm above the neck. The manometer was taken into a chamber used for training astronauts. What is the highest pressure that can be read with assurance on this manometer?

A)62.0 torr
B)62.5 torr
C)980 torr
D)98.5 torr
E)620 torr

Answer 2

620 torr

Question 3

A U.S. Weather Bureau forecast cited the atmospheric pressure at sea level as having a value of 768.2 mm Hg. What would the value be in kPa? (1 atm = 101325 Pa = 760 torr = 760 mm Hg = 1.01325 bar = 1013.25 mb)

A)778.4 kPa
B)102.4 kPa
C)100.3 kPa
D)91.62 kPa
E)1024 kPa

Answer 3

102.4 kPa

Question 4

The barometric pressure in a cavern was measured using a mercury barometer. A value of 74.2 cm of Hg was obtained. How many atmospheres is this?

A)5.64 atm
B)9.76 atm
C)1.024 atm
D)0.976 atm
E)0.0976 atm

Question 5

A pressure measured using a mercury barometer results in a mercury column height of 356 mm. What column height of water would be needed to measure the same pressure? The density of mercury is 13.6 g/cm³; the density of water is 1.00 g/cm³.

A)52 cm
B)484 cm
C)26.18 mm
D)38.2 cm
E)207 cm

Question 6

An open-end mercury manometer was constructed from a U-shaped tube and connected to a gas container. In a particular measurement, the level in the end of the tube connected to the gas container measured 76.2 cm above the U-neck, while the level in the open end (to the atmosphere)was 23.8 cm above the U-neck. The outside air pressure in the laboratory was measured as 754 torr. What is the pressure in the gas container?

A)230 torr
B)236 torr
C)702 torr
D)806 torr
E)1278 torr

Question 7

An open-end mercury manometer was constructed from a U-shaped tube and connected to a gas container. In a particular measurement, the level in the end of the tube connected to the gas container measured 82.8 cm above the U-neck, while the level in the open end (to the atmosphere)was 17.2 cm above the U-neck. The outside air pressure in the laboratory was measured as 764 torr. What is the pressure in the gas container?

A)108 torr
B)159 torr
C)698 torr
D)830 torr
E)1420 torr

Question 8

An open-end mercury manometer was constructed from a U-shaped tube and connected to a gas container. In a particular measurement, the level in the end of the tube connected to the gas container measured 62.0 cm above the U-neck, while the level in the open end (to the atmosphere)was 23.8 cm above the U-neck. The outside air pressure in the laboratory was measured as 772 torr. What is the pressure in the gas container?

A)206 torr
B)390 torr
C)734 torr
D)810 torr
E)1154 torr

Question 9

A closed-end mercury manometer is being used to measure gas pressure in a container designed for studies on the gases. In a particular experiment, the mercury in the closed end of this manometer was 622 mm above the U-neck, while the level in the end connected to the container was measured as 252 mm above the U-neck. What is the pressure, in torr, in the gas collection manifold?

A)206 torr
B)308 torr
C)370 torr
D)390 torr
E)1130 torr

Question 10

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 6.414 liters when the pressure was 850 torr and the temperature was 27.2 ^°C. The pressure was readjusted to 4423 torr by moving the piston. What is the volume occupied by the sample under the new conditions if the temperature remained constant throughout?

A)0.837 L
B)0.937 L
C)1.23 L
D)1.53 L
E)3.34 L

Question 11

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 4.626 liters when the pressure was 0.983 atm and the temperature was 27.2°C. The pressure was readjusted to 1.388 atm by moving the piston. What is the volume occupied by the sample under the new conditions if the temperature remained constant throughout?

A)0.303 L
B)3.28 L
C)4.68 L
D)6.35 L
E)6.49 L

Question 12

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 2.86 cubic meters when the pressure was 9.85 × 10⁴ Pa and the temperature was 25.8°C. The pressure was readjusted to 1.08 × 10⁵ Pa by moving the piston. What is the volume occupied by the sample under the new conditions if the temperature remained constant throughout?

A)0.383 m³
B)2.61 m³
C)3.14 m³
D)8.23 m³
E)26.1 m³

Question 13

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 1.40 liters when the pressure was 762 torr and the temperature was 26.9°C. The volume of the system was readjusted to 0.150 liters by moving the piston. What is the pressure exerted on the surface of the piston by the gas if the temperature of the system remained constant?

A)13.4 atm
B)883 atm
C)918 atm
D)1020 atm
E)9.36 atm

Question 14

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 8.50 liters when the pressure was 9.85 × 10⁴ Pa and the temperature was 24.9°C. The volume of the system was readjusted to 11.6 liters by moving the piston. What is the pressure exerted on the surface of the piston by the gas if the temperature of the system remained constant?

A)7.22 Pa
B)2.66 × 10⁴ Pa
C)7.22 × 10⁴ Pa
D)1.34 × 10⁵ Pa
E)3.90 × 10⁵ Pa

Question 15

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 11.60 liters when the pressure was 9.97 × 10⁴ Pa and the temperature was 24.9°C. The volume of the system was readjusted to 8.50 liters by moving the piston. What is the pressure exerted on the surface of the piston by the gas if the temperature of the system remained constant?

A)1.011 × 10³ Pa
B)1.36 × 10⁵ Pa
C)7.31 × 10⁴ Pa
D)1.01 × 10⁵ Pa
E)9.83 × 10⁴ Pa

Question 16

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 1.40 liters when the pressure was 768 torr and the temperature was 26.9 °C. The volume of the system was readjusted to 2.16 liters by changing the temperature while the load on the piston was kept constant to keep the pressure in the system constant. What is the temperature in the system at this point?

A)41.5 °C
B)41.9 °C
C)189.8 °C
D)194.7 °C
E)288.6 °C

Question 17

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 0.00256 cubic meters when the pressure was 1.20 × 10⁵ Pa and the temperature was 77.8 °C. The volume of the system was readjusted to 1.88 liters by changing the temperature while the load on the piston was kept constant to keep the pressure in the system constant. What is the temperature in the system at this point?

A)?15.4 °C
B)+36.1 °C
C)+57.1 °C
D)+204.7 °C
E)+571 °C

Question 18

A cylinder fitted with a movable piston and filled with a gas has a volume of 188.5 mL at 26.7 °C when the applied pressure is 755.2 torr. The temperature of the oil bath surrounding the cylinder was increased to 165.2 °C and the load on the piston was changed. Careful measurement now gave a value of 210.5 mL for the volume. What is the final pressure in the system?

A)462.6 torr
B)576.9 torr
C)715.5 torr
D)988.6 torr
E)1233 torr

Question 19

A cylinder fitted with a movable piston and filled with a gas has a volume of 16.44 liters at 22.4 °C when the applied pressure is 772.2 torr. The temperature of the oil bath surrounding it was increased to 184.4 °C and the load on the piston was changed. Careful measurement now gave a value of 16.60 liters for the volume. What is the final pressure in the system?

A)494.0 torr
B)503.6 torr
C)1184 torr
D)1207 torr
E)6295 torr

Question 20

The standard reference conditions for gases has the values

A)temperature: 0.00 K; pressure: 1.000 standard atmosphere.
B)temperature: 0.00 °C; pressure: 1.000 standard atmosphere.
C)temperature: 273.15 K; pressure: 1.000 Pascal.
D)temperature: 298.15 K; pressure: 1.000 standard atmosphere.
E)temperature: 298.15 K; pressure: 1.000 Pascal.

Question 21

A sample of an unknown gas was isolated in a gas containment bulb on a manifold used in this type of work. The volume of the bulb was 1.425 liters. The temperature was 25.40 °C, and the manifold pressure was 583.0 torr. What volume would this gas sample occupy at STP?

A)1.000 L
B)1.195 L
C)1.700 L
D)2.030 L
E)11.76 L

Question 22

A sample of a gas was isolated in a gas containment bulb on a manifold used in this type work. The volume of the bulb was 1.524 liters. The temperature was 28.40 °C, and the manifold pressure was 637.6 torr. What volume would this gas sample occupy at STP?

A)1.069 L
B)1.158 L
C)1.412 L
D)1.645 L
E)2.006 L

Question 23

A sample of a gas was isolated in a gas containment chamber. The volume of the chamber was 1.245 cubic meters. The temperature was 22.80 °C, and the pressure was 88.26 kPa. What volume would this gas sample occupy at STP?

A)1.001 m³
B)1.009 m³
C)1.175 m³
D)1.319 m³
E)1.549 m³

Question 24

A sample of a gas occupies a volume of 1.820 liters at STP. What pressure would it exert if transferred to a 1.425-liter vessel in which its temperature was raised to 25.2 °C?

A)0.7168 atm
B)0.8552 atm
C)1.169 atm
D)1.278 atm
E)1.395 atm

Question 25

A sample of a gas occupies a volume of 185.5 mL at STP. What pressure would it exert if it was transferred to a gas bulb with a volume of 255.5 mL in which the temperature is maintained at 34.5 °C?

A)489.9 torr
B)569.4 torr
C)621.5 torr
D)929.4 torr
E)1179 torr

Question 26

A sample of a gas occupies a volume of 185.5 mL at 20.2 °C and 0.945 atm. What pressure would it exert if it was transferred to a gas bulb with a volume of 255.5 mL in which the temperature is increased to 34.5 °C?

A)1.39 torr
B)547 torr
C)649 torr
D)891 torr
E)1056 torr

Question 27

A sample of a gas occupies a volume of 1.462 liters at STP. It was placed in a different vessel in which the pressure was measured as 722.5 torr when the temperature was 25.20 °C. What is the volume of this new vessel?

A)1.272 liters
B)1.408 liters
C)1.518 liters
D)1.539 liters
E)1.680 liters

Question 28

A sample of a gas occupies a volume of 1.462 liters at 30.00°C and 1.250 atm. It was placed in a different vessel in which the pressure was measured as 722.5 torr when the temperature was 25.20 °C. What is the volume of this new vessel?

A)2.125 × 10^-3 liters
B)0.5285 liters
C)1.892 liters
D)1.615 liters
E)470.7 liters

Question 29

A sample of a gas occupies a volume of 1.462 liters at STP. It was placed in a different vessel with a volume of 1.601 liters, in which the pressure was measured as 722.0 torr. What is its temperature in this new vessel?

A)-32.6 °C
B)-10.6 °C
C)+11.0 °C
D)+37.0 °C
E)+41.7 °C

Question 30

A sample of a gas occupies a volume of 1.246 liters at STP. It was placed in a different vessel with a volume of 1.410 liters, in which the pressure was measured as 108.5 kPa. What is its temperature in this new vessel?

A)-47.7 °C
B)-14.7 °C
C)+15.5 °C
D)+57.8 °C
E)+88.1 °C

Question 31

A sample of a gas occupies a volume of 122.4 mL at STP. It was placed in a different vessel with a volume of 164.2 mL in which the pressure was measured as 0.9915 atm. What is its temperature in this new vessel?

A)90.2 °C
B)96.4 °C
C)123.4 °C
D)201.9 °C
E)205.4 °C

Question 32

A sample of a gas occupies a volume of 122.4 mL at 25°C and 1.45 atm. It was placed in a different vessel with a volume of 164.2 mL, in which the pressure was measured as 0.9915 atm. What is its temperature in this new vessel?

A)-176.0 °C
B)0.346 °C
C)176 °C
D)22.9 °C
E)1155.8 °C

Question 33

How many liters of pure oxygen gas, measured at STP, are required for the complete combustion of 11.2 L of methane gas (CH₄), also measured at STP?

A)11.2 L
B)16.8 L
C)22.4 L
D)32.0 L
E)33.6 L

Question 34

How many liters of pure oxygen gas, measured at STP, are required for the complete combustion of 16.6 L of ethylene gas (C₂H₄), also measured at STP?

A)16.6 L
B)22.4 L
C)24.9 L
D)33.2 L
E)49.8 L

Question 35

A chemical reaction is shown: 2NO(g)+ O₂(g)? 2NO₂(g). How many liters of pure oxygen gas, measured at STP, are required for the complete reaction with 8.82 L of NO(g), also measured at STP?

A)4.41 L
B)8.82 L
C)11.2 L
D)17.6 L
E)22.4 L

Question 36

How many liters of pure oxygen gas, measured at 45.2 °C and 104.0 kPa, are required for the complete combustion of 5.60 L of acetaldehyde gas (C₂H₄O), measured under the same conditions of temperature and pressure?

A)4.93 L
B)12.3 L
C)14.0 L
D)14.8 L
E)16.8 L

Question 37

A gas sample weighing 3.78 grams occupies a volume of 2.28 L at STP. What is the molecular mass of the sample?

A)8.54 g mol ^-1
B)13.5 g mol ^-1
C)37.1 g mol ^-1
D)51.1 g mol ^-1
E)193 g mol ^-1

Question 38

Two moles of carbon dioxide gas at 35°C are heated to 250°C in a container while the volume is kept constant. The density of the gas in the container will

A)increase.
B)decrease.
C)remain the same.
D)reach a value of zero.
E)There is not enough information given to correctly answer this question.

Question 39

Which of the following gases will have the greatest density at the same specified temperature and pressure?

A)He
B)SF₆
C)CO₂
D)CH₄
E)CFH₃

Question 40

A gas sample weighing 4.48 grams occupies a volume of 2.15 L at STP. What is the molecular mass of the sample?

A)9.63 g mol ^-1
B)10.8 g mol ^-1
C)46.7 g mol ^-1
D)113 g mol ^-1
E)216 g mol ^-1

Question 41

A gas container has a volume of 5.604 L. It contains carbon monoxide gas at 28.2 ^°C. The pressure in the container is 868.5 torr. If the gas behaves as an ideal gas, how much should the gas sample weigh?

A)0.765 g
B)1.28 g
C)5.55 g
D)6.28 g
E)7.25 g

Question 42

What volume would 11.2 g of a gaseous compound occupy at STP if its molecular weight is 44.0 g/mole and it behaves as an ideal gas?

A)5.71 liters
B)11.0 liters
C)11.2 liters
D)22.4 liters
E)44.0 liters

Question 43

What volume would 11.2 g of a gaseous compound occupy at STP if its molecular weight is 56.0 g/mole and it behaves as an ideal gas?

A)4.48 liters
B)5.60 liters
C)11.2 liters
D)44.8 liters
E)110 liters

Question 44

A gas sample occupies a volume of 18.86 liters when the temperature is 35.2 ^°C and the pressure is 735.5 torr. How many moles of gas are in the sample?

A)0.721 moles
B)0.770 moles
C)1.29 moles
D)5.41 moles
E)6.31 moles

Question 45

A gas sample containing 0.2820 moles of a compound is trapped in a vessel at a temperature of 25.2 °C and a pressure of 642.0 torr. What is the volume of the vessel?

A)0.0107 liters
B)0.690 liters
C)8.18 liters
D)12.7 liters
E)92.9 liters

Question 46

A gas sample containing 0.3250 moles of a compound is confined in a glass vessel at a temperature of 28.4 °C and a pressure of 846 torr. What is the volume of the vessel?

A)7.23 × 10^-3 m³
B)737 × 10^-3 m³
C)72.2 × 10^-3 m³
D)77.2 × 10^-3 m³
E)7.8 × 10^-3 m³

Question 47

A gas sample containing 0.2820 moles of a compound is trapped in a 2.461 liter vessel at a temperature of 25.2 °C. What is the pressure in the vessel if it behaves as an ideal gas?

A)0.236 atm
B)0.374 atm
C)2.81 atm
D)4.11 atm
E)24.0 atm

Question 48

A gas sample containing 0.3525 moles of a compound is trapped in a 2.641 liter vessel at a temperature of 28.4 °C. What is the pressure in the vessel if the gas behaves as an ideal gas?

A)334.6 torr
B)2007 torr
C)2510 torr
D)2513 torr
E)2694 torr

Question 49

A gas sample containing 0.3250 moles of a compound is trapped in a chamber with a volume of 2.460 liters. If the temperature of the gas is 26.8 °C, what is its pressure? Assume the gas exhibits ideal gas behavior.

A)220.8 torr
B)2300 torr
C)2471 torr
D)2670 torr
E)24.3 × 10³ torr

Question 50

A gas sample occupies a volume of 1.66 L when the temperature is 150.0 °C and the pressure is 842 torr. How many molecules are in the sample?

A)1.52 × 10²²
B)2.60 × 10²²
C)3.19 × 10²²
D)9.01 × 10²²
E)9.42 × 10²¹

Question 51

A gas sample occupies a volume of 1.446 L when the temperature is 185.0 °C and the pressure is 624 torr. How many molecules are in the sample?

A)1.90 × 10²²
B)2.82 × 10²²
C)4.71 × 10²²
D)9.10 × 10²¹
E)9.10 × 10²²

Question 52

A gas sample occupies a volume of 1.264 L when the temperature is 168.0 °C and the pressure is 946.6 torr. How many molecules are in the sample?

A)2.07 × 10²²
B)2.62 × 10²²
C)2.65 × 10²³
D)2.65 × 10²⁴
E)6.88 × 10²²

Question 53

A student doing a laboratory study on determination of molecular mass of gases obtained the following data for one of his unknowns: 6.155 grams of the gas occupied a volume of 1484 mL when its temperature was 27.3 °C and its pressure was 747.2 torr. Calculate the molecular mass of the gas, assuming ideal gas behavior.

A)13.87 g mol ^-1
B)30.40 g mol ^-1
C)104.0 g mol ^-1
D)106.7 g mol ^-1
E)110.0 g mol ^-1

Question 54

A gas container has a volume of 6.504 L. When filled with propane gas, C₃H₈, at 28.3 °C, the pressure is 486.3 torr. How much should the gas sample weigh?

A)4.67 g
B)7.41 g
C)7.52 g
D)18.1 g
E)263 g

Question 55

A chemical reaction, A(s) $\rarr$ B(s)+ C(g), occurs when substance A is strongly heated. The molecular mass of the gaseous product was to be determined from the following experimental data: Mass of A before reaction starts: 4.962 g
Mass of A after reaction finishes: 0 g Mass of residue (B)after cooling and weighing when no more gas was evolved: 3.684 g When all of the gas C evolved was collected and stored in a 658.5 mL glass vessel at 30.4 °C, the gas exerted a pressure of 748.5 torr.From this data, determine the apparent molecular mass of C, assuming it behaves as an ideal gas.

A)6.54 g mol ^-1
B)47.5 g mol ^-1
C)49.1 g mol ^-1
D)71.6 g mol ^-1
E)141 g mol ^-1

Question 56

A chemical reaction, A(s) $\rarr$ B(s)+ C(g), occurs when substance A is strongly heated. The molecular mass of the gaseous product was to be determined from the following experimental data: Mass of A before reaction starts: 5.467 g
Mass of A after reaction finishes: 0 g Mass of residue (B)after cooling and weighing when no more gas was evolved: 4.762 g When all of the gas C evolved was collected and stored in an 875.0 mL glass vessel at 30.50 °C, the gas exerted a pressure of 346.0 torr.From this data, determine the apparent molecular mass of C assuming it behaves as an ideal gas.

A)4.43 g mol ^-1
B)0.0579 g mol ^-1
C)17.27 g mol ^-1
D)18.35 g mol ^-1
E)44.01 g mol ^-1

Question 57

What is the mole fraction of hydrogen in a gaseous mixture that consists of 8.00 g of hydrogen and 12.00 g of neon in a 3.50-liter container maintained at 35.20 °C?

A)0.150
B)0.400
C)0.660
D)0.870
E)0.930

Question 58

A sealed glass container contains 0.2 moles of O₂ gas and 0.3 moles of N₂ gas. If the total pressure inside the container is 0.75 atm what is the partial pressure of O₂ in the glass container?

A)0.20 atm
B)0.30 atm
C)0.50 atm
D)0.75 atm
E)0.45 atm

Question 59

A sealed glass container contains 0.8 moles of O₂ gas and 0.4 moles of N₂ gas. If the total pressure inside the container is 0.90 atm, what is the partial pressure of O₂ in theglass container?

A)0.40 atm
B)0.90 atm
C)0.60 atm
D)0.67 atm
E)0.30 atm

Question 60

A sealed glass container contains partial pressures of 0.24 atm O₂ gas and 0.46 atm H₂ gas. What is the mole fraction of H₂ in the glass container?

A)0.70
B)0.24
C)0.46
D)0.66
E)0.34

Question 61

A sealed glass container contains partial pressures of 0.80 atm CO₂ gas and 0.35 atm N₂ gas. What is the mole fraction of N₂ in the glass container?

A)0.35
B)1.15
C)0.70
D)0.80
E)0.30

Question 62

A sealed glass container contains partial pressures of 0.24 atm O₂, 0.45 atm CO₂, 0.64 atm N₂, and 0.46 atm H₂ gas in a 3.5 L container at 30.5°C. What is the total pressure exerted on the walls of the container?

A)1.79 atm
B)6.27 atm
C)0.51 atm
D)1902 atm
E)0.64 atm

Question 63

A mixture of 5.00 moles of neon and 3.00 moles of nitrogen occupy a volume of 36.0 L in a vessel where the total pressure is 6.00 atm. The partial pressure of the neon in the container is

A)0.375 atm.
B)0.625 atm.
C)0.833 atm.
D)3.75 atm.
E)43.2 atm.

Question 64

What is the total pressure exerted by a gaseous mixture that consists of 8.00 g of methane and 12.00 g of ethane, C₂H₆, in a 3.50 L container maintained at 35.20 °C?

A)0.400 atm
B)0.741 atm
C)3.13 atm
D)6.49 atm
E)16.5 atm

Question 65

What is the total pressure exerted by a gaseous mixture that consists of 1.00 g of hydrogen and 8.00 g of neon in a 2.80 L container maintained at 44.10 °C?

A)1.15 atm
B)3.77 atm
C)3.95 atm
D)8.30 atm
E)12.9 atm

Question 66

What is the total pressure exerted by a gaseous mixture that consists of 8.00 g of methane and 8.00 g of ethane (C₂H₆)in a 3.50-liter container maintained at 35.20 °C?

A)0.286 atm
B)0.631 atm
C)2.51 atm
D)5.53 atm
E)30.7 atm

Question 67

What is the mole fraction of methane in a gaseous mixture that consists of 8.00 g of methane and 12.00 g of ethane (C₂H₆)in a 3.50 L container maintained at 35.20 °C?

A)0.400
B)0.434
C)0.556
D)0.800
E)1.50

Question 68

A sample of oxygen gas was collected by displacement of water in a gas collection apparatus. The total pressure in the collection vessel was 744.2 torr, the temperature was 26.0 °C, and the vessel contained 522 mL of the collected gas. How many moles of oxygen were collected? (At 26.0 °C, the vapor pressure of water is 25.2 torr.)

A)0.0201 moles
B)0.0215 moles
C)0.0842 moles
D)0.151 moles
E)0.231 moles

Question 69

A sample of hydrogen gas was collected by displacement of water in a large gas buret. The total pressure in the buret was measured as 764.2 torr, the temperature was 23.0 °C, and the buret contained 511 mL of the collected gas. How many moles of hydrogen were collected?(At 23.0 °C, the vapor pressure of water is 21.1 torr.)

A)0.0191 moles
B)0.0206 moles
C)0.0211 moles
D)0.0215 moles
E)0.0217 moles

Question 70

A sample of nitrogen gas was collected by displacement of water in a gas collection flask. The total pressure in the collection flask was measured as 754.2 torr, the temperature was 20.0 °C, and the measured volume of gas collected was 516 mL. How many grams should the nitrogen weigh? (At 20.0 °C, the vapor pressure of water is 17.5 torr.)

A)0.291 g
B)0.305 g
C)0.582 g
D)0.596 g
E)0.610 g

Question 71

A sample of methane gas (CH₄)was collected by displacement of water in a gas collection flask. The total pressure in the collection flask was measured as 758.2 torr, the temperature was 25.0 °C, and the measured volume of gas in the flask was 526.0 mL. How many grams should the methane weigh? (At 25.0 °C, the vapor pressure of water is 23.8 torr.)

A)0.01080 g
B)0.3333 g
C)0.3441 g
D)0.3549 g
E)8.438 g

Question 72

A gas mixture contains 5.00 liters of a mixture of nitrogen gas and oxygen gas. The total pressure in the tank is 38.6 atm when the temperature is 25.0 °C, and the mole fraction of oxygen is 0.400. How much does the oxygen in the tank weigh?

A)50.5 g
B)88.3 g
C)101 g
D)126 g
E)3.01 × 10² g

Question 73

A gas mixture is 50.00% helium and 50.00% methane, by volume. What is the mole fraction of methane in the mixture?

A)0.1997
B)0.2005
C)0.2500
D)0.5000
E)0.8003

Question 74

A gaseous substance effuses twice as rapidly as sulfur dioxide gas. The gas could be

A)carbon monoxide.
B)helium.
C)hydrogen.
D)methane.
E)oxygen.

Question 75

The average speed at which a nitrogen molecule effuses at 30.0 °C is 480 meters per second. The average speed at which a butene molecule (C₄H₈)effuses at this same temperature should therefore be

A)120 m s^-1.
B)170 m s^-1.
C)240 m s^-1.
D)339 m s^-1.
E)679 m s^-1.

Question 76

The average speed at which a methane molecule effuses at 28.5 °C is 631 meters per second. The average speed at which krypton gas effuses at this same temperature should therefore be

A)121 m s^-1.
B)276 m s^-1.
C)315 m s^-1.
D)417 m s^-1.
E)631 m s^-1.

Question 77

1.000 atm of dry nitrogen, placed in a container having a pinhole opening in its side, leaks from the container 2.28 times faster than does 1.000 atm of an unknown gas placed in this same apparatus. Which of the following species could be the unknown gas?

A)NH₃
B)C₄H₁₀
C)SF₆
D)UF₆
E)Rn

Question 78

The average speed at which a methane molecule effuses at 28.5 °C is 631 meters per second. The average speed at which an argon molecule effuses at this same temperature should therefore be

A)253 m s^-1.
B)315 m s^-1.
C)400 m s^-1.
D)502 m s^-1.
E)631 m s^-1.

Question 79

According to the kinetic theory of gases, the average kinetic energy of the gas particles in a gas sample is directly proportional to the

A)pressure.
B)volume.
C)temperature.
D)molar mass.
E)number of moles of gas.

Question 80

If container "A"is occupied by 1.00 mole of oxygen gas while container "B"is occupied by 20.0 grams of nitrogen gas and both containers are maintained at 0.00 °C and 650 torr then,

A)container "B" must be larger than container "A".
B)the average speed of the molecules in container "A" is greater than that of the molecules in container "B".
C)container "A" must have a volume of 22.4 L.
D)the average kinetic energy of the molecules in "A" is equal to the average kinetic energy of the molecules in "B".
E)the number of atoms in container "B" is greater than the number of atoms in container "A".