Deck 10: Properties of Gases the Air We Breathe

Question 1

_____is how gases spread among each other; ____is how gases escape through a hole in a container.

A)Diffusion; effusion
B)Effusion; diffusion
C)Effusion; effusion
D)Diffusion; diffusion

Answer 1

Diffusion; effusion

Question 2

Which set of gases is listed from highest to lowest root-mean-square speed at 25 $\degree$ C?

A)HCN $\gt$ Cl₂ $\gt$ CO₂ $\gt$ HBr
B)CO₂ $\gt$ HCN $\gt$ Cl₂ $\gt$ HBr
C)HBr $\gt$ Cl₂ $\gt$ HCN $\gt$ CO₂
D)HBr $\gt$ Cl₂ $\gt$ CO₂ $\gt$ HCN
E)HCN $\gt$ CO₂ $\gt$ Cl₂ $\gt$ HBr

Answer 2

HCN $\gt$ CO₂ $\gt$ Cl₂ $\gt$ HBr

Question 3

Which of the following statements regarding the kinetic molecular theory of gases is NOT correct?

A)The gas particles are assumed to occupy negligible volume.
B)At a given temperature, the gas particles have the same velocity.
C)The gas particles are in constant, rapid, random motion.
D)The average kinetic energy of the gas particles is directly proportional to the absolute temperature.
E)Energy can be transferred but not lost as gas particles collide with each other and the container walls.

Answer 3

At a given temperature, the gas particles have the same velocity.

Question 4

Which of the following is NOT an assumption made in the kinetic molecular theory of gases?

A)The size of a molecule is negligible.
B)Gas molecules move constantly and randomly throughout the space they occupy.
C)The average kinetic energy of a gas molecule is directly proportional to the absolute temperature of the gas.
D)Collisions of gas molecules with each other and with the walls of the container are elastic.
E)Gas molecules attract and repel each other.

Question 5

Which of the following statements regarding how gases occupy container volumes is NOT correct?

A)Gases fill the entire volume of a container regardless of pressure.
B)The pressure exerted by a sample of gas in a container at a given temperature is uniform in all directions.
C)As the temperature decreases, the fraction of the container volume occupied by gas molecules decreases.
D)The volume unoccupied by gas molecules is spread uniformly throughout the container volume.
E)If gases confined to a smaller volume are allowed to enter a larger volume, they expand and distribute evenly throughout the new space available.

Question 6

Which set of gases is listed from lowest to highest root-mean-square speed at 25 $\degree$ C?

A)Ne $\lt$ NO $\lt$ Ar $\lt$ CH₄
B)Ar $\lt$ CH₄ $\lt$ NO $\lt$ Ne
C)CH₄ $\lt$ NO $\lt$ Ar $\lt$ Ne
D)Ar $\lt$ NO $\lt$ Ne $\lt$ CH₄
E)CH₄ $\lt$ Ne $\lt$ NO $\lt$ Ar

Question 7

The kinetic theory of gases assumes that collisions

A)with the walls of the container cause energy to be lost.
B)of molecules with each other cause energy to be lost.
C)are caused by molecules attracting each other.
D)do not result in a change in the energy of the molecules.
E)do not occur because the size of the molecules is negligible.

Question 8

Which of these gases (Ar, N₂O, H₂) has the same average kinetic energy at 25 $\degree$ C as CO₂?

A)Ar
B)N₂O
C)H₂
D)They are all the same as CO₂.
E)They are all different from CO₂.

Question 9

Which of the following statements regarding ideal gases is NOT correct?

A)All gases are miscible with one another.
B)The pressure exerted by a gas increases as the amount of gas increases.
C)The rates at which gases travel are inversely proportional to their molar masses.
D)The fraction of a container occupied by the gas depends on its temperature.
E)The density of a gas is proportional to its molar mass at a given temperature and pressure.

Question 10

Which of the following statements regarding the density of gases is NOT correct?

A)The density of a gas is inversely proportional to its molar mass.
B)As the temperature goes up, the density of a gas does down.
C)The gas phase of a substance has a much lower density than the liquid or solid phase.
D)As volume increases, density decreases.
E)If the pressure on a gas increases, its density increases.

Question 11

Assuming all of these samples of gas are at the same temperature, which will escape through a hole in a balloon at the lowest rate?

A)20 moles of H₂ in a 12 L balloon
B)3 moles of Xe in an 18 L balloon
C)8 moles of Ne in a 24 L balloon
D)4 moles of Cl₂ in a 16 L balloon
E)12 moles of He in a 24 L balloon

Question 12

A gas is contained in the piston assembly and allowed to expand as in the following figure.Which point on the graph shows the correct final pressure and volume?

A)A
B)B
C)C
D)D
E)More information is needed.

Question 13

Which of the following statements regarding gas particle speed is NOT correct?

A)Gas particles have a distribution of speeds at a given temperature.
B)The largest number of gas particles travel at the most probable speed.
C)More massive gas particles have lower root-mean-square speeds than lighter particles at a given temperature.
D)Individual gas particles have different kinetic energies at a given temperature.
E)A particle traveling at the average speed has a kinetic energy equal to the average kinetic energy of all the gas particles.

Question 14

The pressure of a gas is inversely proportional to

A)the volume of the gas.
B)the number of gas particles.
C)the temperature of the gas.
D)the mass of gas.
E)the density of the gas.

Question 15

Which of the following statements regarding the mixing of gases is correct?

A)More massive gases settle to the bottom of a container, leaving lighter gases near the top.
B)The relative proportions of gases in a mixture vary throughout the container, depending on the pressure.
C)Nonpolar gases do not mix with polar gases.
D)All gas mixtures are homogeneous.
E)Gases mix more uniformly at lower temperatures.

Question 16

Which of the following statements regarding Graham's law of effusion is correct?

A)Effusion refers to the escape of a gas through a small hole into a region of lower pressure.
B)Gases at higher densities will effuse more rapidly.
C)If the molar mass doubles, the effusion rate doubles.
D)The effusion rate of helium is five times that of neon.
E)The effusion rate of n moles of argon in a 20 L container at 20 $\degree$ C is 10 times that observed with a 2 L container.

Question 17

To which of the following is the volume of a gas NOT directly proportional?

A)the temperature of the gas
B)the number of gas particles
C)the pressure of the gas
D)the average kinetic energy of the gas
E)the density of the gas

Question 18

Which set of gases is listed from slowest to fastest effusion rate?

A)Xe $\lt$ SO₂ $\lt$ CO₂ $\lt$ SF₄
B)CO₂ $\lt$ SO₂ $\lt$ SF₄ $\lt$ Xe
C)Xe $\lt$ SF₄ $\lt$ SO₂ $\lt$ CO₂
D)CO₂ $\lt$ SF₄ $\lt$ SO₂ $\lt$ Xe
E)Xe $\lt$ SO₂ $\lt$ SF₄ $\lt$ CO₂

Question 19

Which of the following gases will escape through a hole in a balloon at the highest rate?

A)Kr
B)Ar
C)N₂O
D)NO₂
E)NO

Question 20

What is the average kinetic energy in (kJ/mol) of nitrous oxide (N₂O) molecules at 30.0 $\degree$ C?

A)0.906 kJ/mol
B)3.78 kJ/mol
C)288 kJ/mol
D)147 kJ/mol
E)2.52 kJ/mol

Question 21

You need to hold the pressure of N₂O gas in a balloon constant overnight, so you place it in a glove box that may contain a variety of gases.With which gas should you fill the glove box?

A)air ~78% N₂ and 21% O₂)
B)O₂
C)Ar
D)N₂
E)CO₂

Question 22

_____-is how gases escape through a hole in a container; _____is how gases spread among each other.

A)Diffusion; effusion
B)Effusion; diffusion
C)Effusion; effusion
D)Diffusion; diffusion

Question 23

Which set of gases is listed from slowest to fastest diffusion rate?

A)HCN $\lt$ H₂ $\lt$ He $\lt$ O₃
B)H₂ $\lt$ He $\lt$ HCN $\lt$ O₃
C)O₃ $\lt$ HCN $\lt$ He $\lt$ H₂
D)HCN $\lt$ He $\lt$ O₃ $\lt$ H₂
E)H₂ $\lt$ HCN $\lt$ He $\lt$ O₃

Question 24

About how long would it take hydrogen cyanide gas (HCN) to travel 10.0 meters at 25.0C, when its average kinetic energy is 3.72 kJ/mol?
(1 J = 1 kg . m²/s²; 1 mol = 6.02 * 10²³)

A)36.3 microseconds
B)19.1 milliseconds
C)27.0 milliseconds
D)275 milliseconds
E)524 milliseconds

Question 25

The diffusion rate of helium in a lecture hall was found to be 25.0 m/s at 25 $\degree$ C.How long will it take poisonous phosgene gas, COCl₂, to diffuse 10.0 m in the same room?

A)2.01 s
B)0.400 s
C)12.4 s
D)61.8 s
E)9.89 s

Question 26

What is the root-mean-square speed of HF at 37.5 $\degree$ C?

A)6.84 m/s
B)19.7 m/s
C)61.8 m/s
D)216 m/s
E)622 m/s

Question 27

Determine the root-mean-square speed of methane (CH₄) molecules that have an average kinetic energy of 10.5 J/mol.

A)337 m/s
B)1.14 m/s
C)2.81 * 10¹³ m/s
D)36.2 m/s
E)1150 m/s

Question 28

At a given temperature, the effusion rate of nitrogen gas is times the rate of krypton.

A)2.99
B)0.409
C)2.45
D)0.578
E)1.73

Question 29

Helium-neon HeNe) lasers contain a low-pressure mixture of He and Ne gases.How many times greater is the root-mean-square speed of He atoms than Ne atoms in a HeNe laser?

A)5.0
B)0.20
C)2.7
D)1.6
E)0.45

Question 30

Calculate the root-mean-square speed of an O₂ molecule with an average kinetic energy of 6.2 * 10^-21 J at 25C.
(1 J = 1 kg . m²/s²; 1 mol = 6.02 * 10²³)

A)20 pm/s
B)230 km/s
C)480 m/s
D)120 m/s
E)230 m/s

Question 31

Which set of gases is listed from fastest to slowest diffusion rate?

A)N₂ $\gt$ NH₃ $\gt$ Ne $\gt$ OF₂
B)NH₃ $\gt$ Ne $\gt$ N₂ $\gt$ OF₂
C)OF₂ $\gt$ N₂ $\gt$ Ne $\gt$ NH₃
D)N₂ $\gt$ Ne $\gt$ OF₂ $\gt$ NH₃
E)NH₃ $\gt$ N₂ $\gt$ Ne $\gt$ OF₂

Question 32

Air is primarily nitrogen and oxygen, but noble gases such as argon and helium can also be present.The following graph shows the speed distributions for these different gases at the same temperature.Which curve might represent nitrogen?

A)A
B)B
C)C
D)D
E)More information is needed.

Question 33

At a given temperature, the rate at which bromine gas effuses is times the rate of helium gas.

A)0.224
B)0.158
C)6.32
D)4.47
E)0.0250

Question 34

Calculate the average kinetic energy of an N₂ molecule with a root-mean-square speed of 536 m/s.(1 J = 1 kg.m²/s²; 1 mol =6.02 *10²³)

A)1.33 *10^-20 J
B)6.68 * 10^-21 J
C)1.25 * 10^-23 J
D)2.49 *10^-23 J
E)2.67 * 10^-20 J

Question 35

Calculate the average kinetic energy of CO₂ molecules with a root-mean-square speed of 629 m/s.Report your answer in kJ/mol.The mass of one CO₂ molecule is 7.31 * 10^-26 kg. (1 J = 1 kg . m²/s²; 1 mol =6.02 * 10²³)

A)8700 kJ/mol
B)14 kJ/mol
C)17 kJ/mol
D)8.7 kJ/mol
E)28 kJ/mol

Question 36

Which of the following is NOT a correct way to finish the following statement? In a sample of air at a given temperature,

A)the nitrogen and oxygen molecules have the same average speed.
B)the nitrogen and oxygen molecules have the same average kinetic energy.
C)some nitrogen molecules are moving slower than some oxygen molecules.
D)some nitrogen molecules are moving faster than some oxygen molecules.
E)all the molecules are moving.

Question 37

At a given temperature, oxygen gas effuses 1.489 times faster than which of the following gases?

A)CO₂
B)SO₂
C)Kr
D)Xe
E)Cl₂

Question 38

The following graph shows the speed distributions for four different gases, all at the same temperature.Which of the curves is for the lightest gas?

A)A
B)B
C)C
D)D
E)More information is needed.

Question 39

Which of the following will have the fastest effusion rate?

A)1.7 mol H₂ in 5 L
B)0.2 mol Xe in 10 L
C)0.6 mol Ar in 15 L
D)2.5 mol He in 10 L
E)1.3 mol Ne in 20 L

Question 40

The root-mean-square speed of a gas is found to be 488.8 m/s at-14.3 $\degree$ C.What is the identity of the gas?

A)O₂
B)CO₂
C)Ar
D)HCN
E)CH₄

Question 41

If the pressure in the eye of a hurricane is 892 mbar, what is the corresponding pressure in mmHg? Recall that 1.013 bar = 1 atm.

A)881 mmHg
B)678 mmHg
C)669 mmHg
D)904 mmHg
E)687 mmHg

Question 42

A barometer measures a pressure of 745 mmHg.What is this pressure in atm?

A)0.980 atm
B)1.02 atm
C)1.03 * 10⁵ atm
D)1.00 * 10⁴ atm
E)0.556 atm

Question 43

At the top of Mt.Everest, which has a height of 29,029 feet, atmospheric pressure is about 265 torr.Which of the following is NOT equivalent to 265 torr?

A)10.4 in Hg
B)35.3 kPa
C)5.12 psi
D)0.344 bar
E)0.349 atm

Question 44

What height of water in meters) is necessary to measure a pressure of 760 mmHg? The density of mercury is 13.546 g/cm³, and the density of water is 1.00 g/cm³.

A)0.760 m
B)1.03 * 10⁴ m
C)0.103 m
D)10.3 m
E)56.1 mm

Question 45

What force is exerted by a pressure of 2.153 atm on a mercury barometer with an inner diameter of 20.00 mm? Recall that the area of a circle is A = $\pi$ r², 1 N = 1 kg m/s², 1 Pa = 1 N/m², and 1 atm = 1.013*10⁵ Pa.

A)68.52 N
B)14.78 N
C)274.1 N
D)6.852 * 10⁷ N
E)173.6 N

Question 46

On a given day, the atmospheric pressure is reported to be 30.8 inches of mercury.Using 1 atm as normal atmospheric pressure, this day would be classified as

A)hot.
B)dense.
C)low pressure.
D)high pressure.
E)normal.

Question 47

The atmospheric pressure in the eye of a hurricane is found to be 26.6 inches of mercury, which is equivalent to

A)760 mmHg.
B)1.00* 10⁵ Pa.
C)0.889 atm.
D)0.987 bar.
E)0.785 atm.

Question 48

Tungsten hexafluoride is one of the heaviest gases known, with a molar mass of 297.9 g/mol.At a given temperature, how long will it take WF₆ to cover the distance H₂ can travel in 25 seconds?

A)304 s
B)60.7 s
C)51.5 s
D)2.06 s
E)3690 s

Question 49

How many milliliters of mercury would exert a pressure of 235 kPa in a barometer with an inner diameter of 25.4 mm? The density of Hg is 13.546 g/mL.Recall that the area of a circle is A = $\pi$ r², 1 N = 1 kg m/s², 1 Pa = 1 N/m², F = mg, and g = 9.81 m/s².

A)164 mL
B)3580 mL
C)896 mL
D)119 mL
E)8.79 mL

Question 50

Air, which is primarily nitrogen and oxygen, does contain a very small fraction of helium.What is the root-mean-square speed of helium at 25 $\degree$ C, where its average kinetic energy is about 3.72 kJ/mol? How many times faster or slower does it travel than N₂? (1 J =1 kg .m²/s²; 1 mol =6.02 *10²³)

A)1360 m/s; 2.65 times faster
B)515 m/s; 0.378 times slower
C)1860 km/s; 7.00 times faster
D)1360 km/s; 0.143 times slower
E)Both gases have the same u_rms at 25 $\degree$ C.

Question 51

You wish to measure the changes in pressures of gases during the course of a reaction using a closed-end mercury manometer.Suppose 758 mmHg N₂O₄ is allowed to react to form NO₂ according to the reaction N₂O₄ (g) $\rightarrow$ 2 NO₂ (g).The total pressure you measure as the reaction proceeds is the sum of the pressures of N₂O₄ and NO₂ present.When the total pressure is 1039 mmHg, what is the pressure of N₂O₄?

A)477 mmHg
B)281 mmHg
C)576 mmHg
D)379 mmHg
E)553 mmHg

Question 52

What is the pressure in the gas bulb connected to the mercury manometer shown in the diagram if the ambient pressure is 756 torr? The heights labeled in the diagram are 15 mm and 21 mm.

A)762 torr
B)778 torr
C)735 torr
D)771 torr
E)741 torr

Question 53

At a given temperature, an unknown gas takes 10.0 minutes to travel the distance helium gas travels in 1.66 minutes.What is the approximate molar mass of the unknown gas?

A)24.1 g/mol
B)68.9 g/mol
C)241 g/mol
D)36.3 g/mol
E)145 g/mol

Question 54

Which of the following statements regarding instruments for measuring the pressures of gases is NOT correct?

A)A barometer is most often used to measure the pressures of samples of gas.
B)Open-end manometers are particularly useful for measuring gas pressures that are higher than atmospheric pressure.
C)Pressure sensors usually employ flexible diaphragms that distort based on changes in pressure.
D)The pressure of a gas connected to a closed-end mercury manometer is directly measured by the height of the mercury column observed.
E)The change in the height of the mercury column observed when a sample of gas is connected to an open-end manometer is directly related to the difference in the gas pressure and atmospheric pressure.

Question 55

Two identical cement blocks are placed on a glass table in different positions, as shown in the diagram.Which statement about these blocks is correct?

A)A exerts more pressure on the table.
B)B exerts more pressure on the table.
C)Both blocks exert the same pressure on the table.
D)A exerts more force on the table.
E)B exerts more force on the table.

Question 56

What pressure will be measured (in Pa) if a gas is exerting a force of 10.00 N on a mercury barometer with an inner diameter of 10.00 mm? Recall that the area of a circle is A = $\pi$ r², 1 N = 1 kg m/s², and 1 Pa = 1 N/m².

A)3.183 * 10⁴ Pa
B)1.273 * 10⁵ Pa
C)1.273 * 10³ Pa
D)3.183 * 10^-2 Pa
E)1.273 * 10^-2 Pa

Question 57

The cold inflation pressure of many car tires is 30.0 psi, which is the gauge pressure.If 1 atm = 14.7 psi, what is the gauge pressure of a car tire in torr?

A)2.04 torr
B)1.55* 10³ torr
C)441 torr
D)0.580 torr
E)1.12 * 10⁴ torr

Question 58

Which of the following substances will require the highest column for measuring an atmospheric pressure of 0.950 atm? Assume all the barometers have columns with the same diameter.)

A)mercury (d = 13.59 g/cm³)
B)ethanol (d = 0.785 g/cm³)
C)ethylene glycol (d = 1.09 g/cm³)
D)water (d = 1.00 g/cm³)
E)carbon tetrachloride (d = 1.58 g/cm³)

Question 59

What pressure (in Pa) will be exerted on the bottom of a 63.5 kg hiker's foot when she stands on a rusty nail? Assume the diameter of the tip of the nail is 1.00 mm.The acceleration due to gravity is 9.81 m/s².Recall that the area of a circle is A = $\pi$ r² and that 1 Pa =1 kg m^-1 s^-2.

A)1.98 * 10² Pa
B)7.93 * 10² Pa
C)1.98 * 10⁸ Pa
D)7.93 * 10⁸ Pa
E)7.93 *10⁵ Pa

Question 60

The atmospheric pressure on Venus is approximately 9.3 MPa.What is this in atm? Recall that 1 bar =0.9869 atm, 1 atm = 101.325 kPa.

A)11 atm
B)9.4 atm
C)94 atm
D)92 atm
E)9.2 atm

Question 61

A sample of gas at -15.0 $\degree$ C is heated in a constant-volume container until the pressure is 65.0% higher than its original value.What is the final temperature of the gas?

A)153 $\degree$ C
B)426 $\degree$ C
C)202 $\degree$ C
D)124 $\degree$ C
E)298 $\degree$ C

Question 62

Which of the following is NOT true?

A)P, V, T, and n for an ideal gas are state functions.
B)The ideal gas equation is PV = nRT, where R is the universal gas constant.
C)STP refers to 273 K and 1 bar, as defined by IUPAC.
D)The molar volume of a gas is the volume that one mole of an ideal gas occupies at STP.
E)The ratio PV/T has a constant value.

Question 63

A sample of nitrogen gas has a volume of 10.0 L at 2.50 atm and 50.0 $\degree$ C.If the pressure is increased to 5.00 atm and the temperature decreases to 25.0 $\degree$ C, what volume does the gas occupy?

A)5.00 L
B)2.50 L
C)5.42 L
D)4.61 L
E)10.0 L

Question 64

A sample of neon gas is contained in a 100.0 L cylinder with a movable piston at 25 $\degree$ C and 0.55 atm.If the absolute temperature doubles and the gas expands at constant pressure, approximately how many joules of P-V work does the gas do?

A)(-1300 J)
B)(-420 J)
C)(-5600 J)
D)(-2500 J)
E)(-940 J)

Question 65

A sample of gas at 875 $\degree$ C is allowed to cool at constant pressure until its volume is one-fourth of its original value.What is the final temperature of the gas?

A)(-54.3 $\degree$ C)
B)13.9 $\degree$ C
C)219 $\degree$ C
D)287 $\degree$ C
E)383 $\degree$ C

Question 66

In an experiment, 25.0 mL of a gas with a pressure of 1.00 atm is contained in a balloon at 25.00 $\degree$ C.The balloon's temperature is adjusted until the pressure is 0.750 atm at a volume of 31.1 mL.What is the final temperature of the gas under the new conditions?

A)23.3 $\degree$ C
B)(-93.4 $\degree$ C)
C)(-46.5 $\degree$ C)
D)5.02 $\degree$ C
E)46.4 $\degree$ C

Question 67

A weather balloon is inflated to 40.0 L and 1.00 atm at 21.3 $\degree$ C.It rises to an altitude where the pressure is 0.280 atm and the temperature is -48.6 $\degree$ C.What is the final volume of the balloon?

A)109 L
B)187 L
C)143 L
D)30.5 L
E)62.6 L

Question 68

Which of the following statements regarding temperature and absolute zero (-273.15 $\degree$ C) is NOT correct?

A)At constant P and n, the volume of a gas decreases as temperature decreases because the average kinetic energy of the particles decreases.
B)When a sample of gas is at any temperature above absolute zero, it implies that the gas has done pressure-volume work as long as there was an opposing pressure).
C)The concept of zero volume of a gas at absolute zero requires that the gas does not condense to form the liquid phase.
D)Equal moles of different gases occupy different volumes at constant pressure, but their extrapolated volume at 0 K appears to be zero.
E)Absolute zero has been reached experimentally by decreasing the volume of a gas to 1/273.15 of its original value.

Question 69

A balloon is filled with 3.00 L of helium at a pressure of 765 torr.What is the volume of the balloon at an altitude where the pressure is 530 torr if the temperature remains constant?

A)0.231 L
B)4.33 L
C)2.08 L
D)1.00 L
E)3.00 L

Question 70

Oxygen gas is formed by the decomposition of potassium chlorate at high temperatures according to the reaction 2 KClO₃ (s) $\rightarrow$ 2 KCl(s)+3 O₂ (g).Suppose 1.23 g KClO₃ is placed in a container connected to an open-end mercury manometer on a day when atmospheric pressure is 1.00 atm.Once the reaction is complete, the height of the mercury column in the U-tube on the side of the reaction container rises by 172 mmHg.What is the pressure of O₂ gas produced by the reaction?

A)1348 torr
B)0.774 atm
C)22.9 kPa
D)0.559 bar
E)36.7 in Hg

Question 71

A gas has a volume of 50.0 mL at 3.50 atm.What is the volume at 372 mmHg if the temperature remains constant?

A)0.470 mL
B)5.31 L
C)0.358 L
D)6.99 mL
E)133 mL

Question 72

What is the molar volume of an ideal gas at 1.00 bar and 0.00 $\degree$ C?

A)22.4 L
B)22.7 L
C)22.1 L
D)15.0 L
E)27.2 L

Question 73

Which of the following statements regarding the gas laws is NOT correct?

A)As temperature increases at constant pressure, the volume increases so that the total force per area exerted by the gas particles on the container walls remains constant.
B)As temperature increases at constant volume, the frequency and energy of the collisions between the particles and the container walls increase.
C)The average number of collisions experienced by the particles can remain constant if the volume of the container can increase as the amount of gas increases at constant temperature and pressure.
D)As temperature increases at constant volume, more particles with higher average kinetic energy collide with each other and the container walls.
E)As particle density increases at constant temperature, the average energy of the collisions between the particles and the container walls decreases.

Question 74

Which of the following is unimportant when using the ideal gas law?

A)the chemical identity of the gas sample
B)the temperature of the gas sample
C)the pressure of the gas sample
D)the volume of the container holding the gas sample
E)the amount of gas

Question 75

A sample of gas at 475.0 $\degree$ C is allowed to cool at constant volume until its pressure is one-fifth of its original value.What is the final temperature of the gas?

A)(-50.67 $\degree$ C)
B)95.00 $\degree$ C
C)273.2 $\degree$ C
D)149.6 $\degree$ C
E)(-123.5 $\degree$ C)

Question 76

A sample of oxygen gas at 25.0 $\degree$ C has its pressure increased 85.0% while its volume is decreased 35.0%.What is the final temperature of the gas?

A)(-80.1 $\degree$ C)
B)85.4 $\degree$ C
C)7.44 $\degree$ C
D)30.1 $\degree$ C
E)575 $\degree$ C

Question 77

You wish to measure the extent of reaction by monitoring pressure changes.Suppose 1.000 atm of tungsten hexafluoride gas at 400.00 $\degree$ C in a 20.0 L deposition chamber partially decomposes to form tungsten metal and fluorine gas.The products of the reaction at this point are cooled to 25.00 $\degree$ C.The resulting pressure, which is due to the sum of the pressures of F₂ and leftover WF₆, is 1.028 atm.What is the pressure due to the unreacted WF₆?
WF6 (g) $\rightarrow$ W(s)+ 3 F₂ (g)

A)0.3395 atm
B)0.6605 atm
C)0.9830 atm
D)0.1230 atm
E)0.1504 atm

Question 78

A sample of argon gas at 2.90 atm and 35.0 mL is heated from 20.0 $\degree$ C to 50.0 $\degree$ C.If the pressure remains constant, what is the final volume of the gas?

A)38.6 mL
B)87.5 mL
C)31.8 mL
D)35.0 mL
E)52.5 mL

Question 79

A sample of neon gas at 745 torr and 60.0 L is compressed to 14.5 L.If the temperature remains constant, what is the final pressure of the gas?

A)1.17 torr
B)180 torr
C)3080 torr
D)761 torr
E)792 torr

Question 80

A sample of helium has a volume of 2.275 L at 10.25 atm and 30.0 $\degree$ C.If the volume is increased to 20.39 L and the temperature decreases to -20.0 $\degree$ C, what pressure does the gas exert?

A)1.37 atm
B)0.730 atm
C)0.136 atm
D)(-0.762 atm)
E)0.955 atm