Deck 10: Gases

Question 1

Which two temperature changes are equivalent?

A)1 K = 1 F°
B)1 F° = 1 C°
C)1 C° = 1 K
D)none of the above

Answer 1

C

Question 2

The root-mean-square speed of the molecules of an ideal gas is v.The gas is now slowly compressed to one-half its original volume with no change in temperature.What is the root-mean-square speed of the molecules now?

A)4v
B)2v
C)v/
D)v
E)v/2

Answer 2

D

Question 3

Two containers of equal volume each hold samples of the same ideal gas.Container A has twice as many molecules as container B.If the gas pressure is the same in the two containers,the correct statement regarding the absolute temperatures T_A and T_B in containers A and B,respectively,is

A)T_A = T_B.
B)T_A = 2T_B.
C)T_A = T_B.
D)T_A = T_B.
E)T_A = T_B.

Answer 3

C

Question 4

When a heavy metal block is supported by a cylindrical vertical post of radius R,it exerts a force F on the post.If the diameter of the post is increased to 2R,what force does the block now exert on the post?

A)F/4
B)F/2
C)F/
D)F
E)2F

Question 5

A compressed gas with a total mass of is stored in a spherical container having a radius of 0.521 m.What is the density of the compressed gas?

A)181 kg/m³
B)110 kg/m³
C)134 kg/m³
D)161 kg/m³

Question 6

When a box rests on a round sheet of wood on the ground,it exerts an average pressure p on the wood.If the wood is replaced by a sheet that has half the diameter of the original piece,what is the new average pressure?

A)4p
B)2p
C)p
D)p/2
E)p/4

Question 7

Consider two equal-volume flasks of gas at the same temperature and pressure.One gas,oxygen,has a molecular mass of 32.The other gas,nitrogen,has a molecular mass of 28.What is the ratio of the number of oxygen molecules to the number of nitrogen molecules in these flasks?

A)
B)
C)
D)
E)

Question 8

An ideal gas is held in a container of volume V at pressure p.The rms speed of a gas molecule under these conditions is v.If now the volume and pressure are changed to 2V and 2p,the rms speed of a molecule will be

A)v/2
B)v
C)2v
D)4v
E)v/4

Question 9

The absolute temperature of a gas is T.In order to double the rms speed of its molecules,what should be the new absolute temperature?

A)4T
B)2T
C)T
D)8T
E)16T

Question 10

A sample of an ideal gas is heated and its Kelvin temperature doubles.If the root-mean-square speed of its molecules was originally v,what is the new root-mean-square speed?

A)4v
B)2v
C)v
D)v/
E)v/4

Question 11

Oxygen molecules are 16 times more massive than hydrogen molecules.At a given temperature,the average molecular kinetic energy of oxygen molecules,compared to that of hydrogen molecules,

A)is greater.
B)is less.
C)is the same.
D)cannot be determined without knowing the pressure and volume.

Question 12

A styrofoam sphere of radius R has a density ρ.You now carefully compress the sphere so its radius is R/2.What is the density of the compressed sphere?

A)2 ρ
B)4 ρ
C)ρ
D)ρ
E)8 ρ

Question 13

The temperature in your classroom is closest to

A)68 K.
B)68°C.
C)50°C.
D)295 K.

Question 14

A fixed container holds oxygen and helium gases at the same temperature.Which of the following statements are correct? (There could be more than one correct choice.)

A)The oxygen molecules have the greater average kinetic energy.
B)The helium molecules have the greater average kinetic energy.
C)The oxygen molecules have the greater speed.
D)The helium molecules have the greater speed.
E)The helium molecules have the same average kinetic as the oxygen molecules.

Question 15

A mole of diatomic oxygen molecules and a mole of diatomic nitrogen molecules are at STP.Which statements are true about these molecules? (There could be more than one correct choice.)

A)Both gases have the same average molecular speeds.
B)Both gases have the same number of molecules.
C)Both gases have the same average kinetic energy per molecule.
D)Both gases have the same average momentum per molecule.

Question 16

A plastic block of dimensions 2.00 cm × 3.00 cm × 4.00 cm has a mass of 30.0 g.What is its density?

A)0.80 g/cm³
B)1.20 g/cm³
C)1.25 g/cm³
D)1.60 g/cm³

Question 17

The absolute temperature of an ideal gas is directly proportional to which of the following quantities?

A)the average speed of its molecules
B)the average momentum of its molecules
C)the average kinetic energy of its molecules
D)the mass of its molecules
E)It is proportional to all of the above quantities.

Question 18

A hollow sphere of negligible mass and radius R is completely filled with a liquid so that its density is ρ.You now enlarge the sphere so its radius is 2R and completely fill it with the same liquid.What is the density of the enlarged sphere?

A)8 ρ
B)4 ρ
C)ρ/2
D)ρ
E)ρ/8

Question 19

Oxygen molecules are 16 times more massive than hydrogen molecules.At a given temperature,how do their average molecular speeds compare? The oxygen molecules are moving

A)four times faster than the hydrogen molecules.
B)at 1/4 the speed of the hydrogen molecules.
C)sixteen times faster than the hydrogen molecules.
D)at 1/16 the speed of the hydrogen molecules.
E)at 1/ the speed of the hydrogen molecules.

Question 20

Substance A has a density of 3 g/cm³ and substance B has a density of 4 g/cm³.In order to obtain equal masses of these two substances,what must be the ratio of the volume of A to the volume of B?

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

Question 21

Express a body temperature 98.6°F in Celsius degrees.

A)37.0°C
B)45.5°C
C)66.6°C
D)72.6°C

Question 22

Calculate the pressure exerted on the ground due to person standing on one foot if the bottom of the person's foot is wide and long.

A)2.1 × 10⁴ Pa
B)2.2 × 10³ Pa
C)4.8 × 10⁴ Pa
D)5.3 × 10⁴ Pa

Question 23

One of the dangers of tornados and hurricanes is the rapid drop in air pressure that is associated with such storms.Assume that the air pressure inside of a sealed house is 1.02 atm when a hurricane hits.The hurricane rapidly decreases the external air pressure to 0.910 atm.What net outward force is exerted on a square window of the house that is on each side? (1.00 atm = 1.01 × 10⁵ Pa)

A)4.59 × 10⁴ N
B)5.19 × 10⁴ N
C)4.82 × 10⁵ N
D)5.42 × 10⁵ N

Question 24

The density of material at the center of a neutron star is approximately 1.00 × 10¹⁸ kg/m³.What is the mass of a cube of this material that is on each side.(One micron is equal to 1.00 × 10^-6 m.)

A)5.45 kg
B)4.74 kg
C)6.16 kg
D)6.70 kg

Question 25

Oxygen condenses into a liquid at approximately 90 K.What temperature,in degrees Fahrenheit,does this correspond to?

A)-193°F
B)-217°F
C)-265°F
D)-297°F

Question 26

A 50.0-N brick has the following measures: 30.0 cm × 10.0 cm × 4.00 cm.What is the maximum pressure it can exert on a horizontal surface due to its interaction with Earth?

A)1.25 Pa
B)12.5 Pa
C)1.25 kPa
D)12.5 kPa

Question 27

Express -40°C in °F.

A)-72°F
B)-54°F
C)-40°F
D)4.4°F

Question 28

A 900-N person is standing on snowshoes.Each snowshoe has area 2500 cm² and has negligible weight.What pressure does this person's exert on the snow due to his interaction with Earth?

A)0.18 N/m²
B)0.36 N/m²
C)1800 N/m²
D)3600 N/m²

Question 29

The temperature changes from 35°F during the night to 75°F during the day.What is the temperature change on the Celsius scale?

A)72 C°
B)40 C°
C)32 C°
D)22 C°

Question 30

A 1200-kg car is supported equally by the four tires,which are inflated to the same gauge pressure.What gauge pressure is required so the area of contact of each tire with the road is 100 cm²?

A)12 × 10⁵ Pa
B)12 × 10⁴ Pa
C)2.9 × 10⁵ Pa
D)2.9 × 10⁴ Pa

Question 31

Nitrogen boils at -196°C.What is the corresponding temperature in the Fahrenheit scale?

A)-315°F
B)-196°F
C)-346°F
D)-290°F
E)-321°F

Question 32

The weather outside is frightful.The temperature is -22°F.What is the corresponding temperature in the Celsius scale?

A)-35°C
B)-30°C
C)-22°C
D)-20°C
E)-12°C

Question 33

At what,if any,temperature are the numerical readings on the Fahrenheit and Celsius scales the same?

A)-30°
B)-40°
C)-50°
D)-60°
E)They can never read the same because they are based on different zeroes.

Question 34

A temperature change of 20 C° corresponds to a Fahrenheit temperature change of

A)68 F°.
B)11 F°.
C)36 F°.
D)18 F°.

Question 35

A 100-kg person sits on a 5-kg bicycle.The force that the person exerts on the bicycle is borne equally by the two wheels of the bicycle.The tires are 2.0 cm wide and are inflated to a gauge pressure of 8.0 × 10⁵ Pa.What length of each tire is in contact with the ground?

A)1.6 cm
B)1.8 cm
C)3.2 cm
D)2.4 cm
E)6.4 cm

Question 36

How many grams of ethanol (density 0.80 g/cm³)should be added to 5.0 g of chloroform (density 1.5 g/cm³)if the resulting mixture is to have a density of 1.2 g/cm³? Assume that the fluids do not change their volumes when they are mixed.

A)2.0 g
B)2.4 g
C)1.8 g
D)4.4 g
E)1.6 g

Question 37

A 1938 nickel has a diameter of 21.21 mm,a thickness of 1.95 mm,and weighs 0.04905 N.What is its density?

A)1.37 × 10^-4 kg/m³
B)1.82 × 10³ kg/m³
C)19.3 × 10³ kg/m³
D)3.63 × 10³ kg/m³
E)7.26 × 10³ kg/m³

Question 38

What is absolute zero on the (a)Celsius scale and (b)on the Fahrenheit scale?

Question 39

Under standard conditions,the density of air is 1.29 kg/m³.What is the mass of the air inside a room measuring 4.0 m × 3.0 m × 2.0 m?

A)0.32 kg
B)3.1 kg
C)31 kg
D)1.9 kg
E)19 kg

Question 40

A round coin has a diameter of 19.55 mm,a thickness of 1.55 mm,and a mass of 2.50 g.What is its density?

A)5.37 × 10³ kg/m³
B)21.5 × 10³ kg/m³
C)1.34 × 10³ kg/m³
D)2.68 × 10³ kg/m³
E)1.86 × 10^-4 kg/m³

Question 41

A gas-filled vertical cylinder,closed at the bottom end,is fitted at the top with a piston that can move freely.The mass of the piston is 10.0 kg,and the initial height of the piston above the bottom of the cylinder is 25 cm.A mass of 8.0 kg is placed on the piston.What is the resulting height of the piston,assuming that the temperature of the ideal gas is kept constant?

A)12 cm
B)13 cm
C)14 cm
D)15 cm
E)16 cm

Question 42

A refrigerator has an interior volume of 0.500 m³.The temperature inside the refrigerator in 282 K,and the pressure is 101 kPa.If the molecular weight of air is 29 g/mol,what is the mass of air inside the refrigerator? (R = 8.31 J/mol × K)

A)625 g
B)513 g
C)447 g
D)329 g
E)243 g

Question 43

A car starts out when the air temperature is 288 K and the absolute (total)air pressure in the tires is 500 kPa.After driving a while,the temperature of the air in the tires increases to 298 K.What is the pressure in the tires at that point,assuming their volume does not change?

A)129 kPa
B)483 kPa
C)507 kPa
D)517 kPa
E)532 kPa

Question 44

A weather balloon containing 2.0 m³ of hydrogen gas rises from a location at which the temperature is 22°C and the pressure is 101 kPa to a location where the temperature is -39°C and the pressure is 20 kPa.If the balloon is free to expand so that the pressure of the gas inside is equal to the ambient pressure,what is the new volume of the balloon?

A)4.0 m³
B)6.0 m³
C)8.0 m³
D)10 m³
E)12 m³

Question 45

How many molecules are in (a)1.0 cm³ of air at STP and (b)1.0 cm³ of helium at STP? (R = 8.31 J/mol ∙ K,N_A = 6.022 × 10²³ molecules/mol)

Question 46

A vertical cylinder,closed at the bottom end,contains 0.0100 mol of ideal gas.It is fitted at the top with a piston that can move freely.The mass of the piston is 14.0 kg and the initial height of the piston above the bottom of the cylinder is 25 cm.What is the temperature of the gas? (R = 8.31 J/mol ∙ K)

A)290 K
B)413 K
C)3620 K
D)405 K
E)500 K

Question 47

Your lungs hold 4.2 L of air at a temperature of 27°C and a pressure of 101.3 kPa.How many moles of air do your lungs hold? (R = 8.31 J/mol ∙ K)

A)0.15 moles
B)0.17 moles
C)0.19 moles
D)0.21 moles
E)0.23 moles

Question 48

A balloon originally has a volume of 1.0 m³ when the gas in it is at 20°C and under a pressure of 1.0 atm.As it rises in the earth's atmosphere,its volume expands.What will be its new volume if its final temperature and pressure are -40°C and 0.10 atm?

A)2.0 m³
B)4.0 m³
C)6.0 m³
D)8.0 m³

Question 49

Platinum melts at 3215°F.What is the corresponding temperature in the Kelvin scale?

A)2041 K
B)2135 K
C)2207 K
D)2296 K
E)3215 K

Question 50

If a certain sample of an ideal gas has a temperature of 104°C and exerts a pressure of 2.3 × 10⁴ Pa on the walls of its container,how many gas molecules are present in each cubic centimeter of volume? The ideal gas constant is R = 8.31 J/mol × K and Avogadro's number is N_A = 6.022 × 10²³ molecules/mol.

Question 51

A certain automobile tire has a volume of 0.0185 m³.If the absolute (or total)pressure in the tire is 500 kPa and the temperature is 298 K,how many molecules are there inside the tire? (R = 8.31 J/mol ∙ K,N_A = 6.022 x 10²³ molecules/mol)

A)2.25 × 10²³ molecules
B)2.25 × 10²⁴ molecules
C)3.25 × 10²³ molecules
D)3.25 × 10²⁴ molecules
E)3.25 × 10²⁵ molecules

Question 52

A quantity of an ideal gas is kept in a rigid container of constant volume.If the gas is originally at a temperature of 19°C,at what temperature will the pressure of the gas double from its original value?

A)91°C
B)38°C
C)311°C
D)273°C
E)122°C

Question 53

A laboratory vacuum pump can reduce the pressure in a chamber to 1.0 × 10^-7 Pa.If the volume of the chamber is 0.500 m³ and the temperature is 27°C,how many molecules are left inside the chamber? (N_A = 6.022 × 10²³ molecules/mol,R = 8.31 J/mol ∙ K)

A)1.2 × 10¹³
B)2.4 × 10¹³
C)1.2 × 10¹²
D)2.4 × 10¹²
E)1.2 × 10¹⁴

Question 54

On a cold day,you take in 4.2 L of air into your lungs at a temperature of 0°C.If you hold your breath until the temperature of the air in your lungs reaches 37°C,what is the volume of the air in your lungs at that point,assuming the pressure does not change?

A)4.2 L
B)4.4 L
C)4.6 L
D)4.8 L
E)5.0 L

Question 55

A 20.0-L pressure vessel holds 2.00 mol of oxygen at 30°C.What is the pressure inside the vessel? (R = 8.31 J/mol ∙ K)

A)101 Pa
B)101 kPa
C)1.01 MPa
D)2.52 MPa
E)252 kPa

Question 56

A jar holds 2.0 L of ideal nitrogen gas,N₂,at STP.The atomic mass of nitrogen is 14.0 g/mol,the ideal gas constant is R = 8.31 J/mol ∙ K,Avogadro's number is N_A = 6.022 × 10²³ molecules/mol,and 1.00 atm = 101 kPa.
(a)How many moles of nitrogen are in the jar?
(b)How many nitrogen molecules are in the jar?
(c)What is the mass of the nitrogen in the jar?

Question 57

How many moles are there in 2.00 kg of copper? The atomic mass of copper is 63.5 g/mol and its density is 8.90 g/cm³.

A)15.3
B)31.5
C)51.3
D)53.1

Question 58

An ideal gas occupies 6.00 × 10² cm³ at 20°C.At what temperature will it occupy 1.20 × 10³ cm³ if the pressure is held constant?

A)10°C
B)40°C
C)100°C
D)313°C

Question 59

Originally 2.00 mol of gas are at standard temperature and pressure If the temperature changes to 47.0°C and the pressure decreases to half of what it was,how many liters do the two moles now occupy? (1 atm = 101 kPa,R = 8.31 J/mol ∙ K)

Question 60

An ideal gas has a pressure of 2.5 atm,a volume of 1.0 L at a temperature of 30°C.How many molecules are there in this gas? (R = 8.31 J/mol ∙ K,1.00 atm = 101 kPa,N_A = 6.022 × 10²³)

A)6.1 × 10²³
B)6.0 × 10²²
C)2.4 × 10²²
D)2.3 × 10²³

Question 61

What is the total translational kinetic energy of the gas in a classroom filled with nitrogen at at The dimensions of the classroom are The Boltzmann constant is 1.3806503 × 10^-23 J/K,R = 8.31 J/mol ∙ K,and N_A = 6.022 × 10²³ molecules/mol.

Question 62

A sealed container holds 0.020 moles of ideal nitrogen (N₂)gas,at a pressure of 1.5 atm and a temperature of 290 K.The atomic mass of nitrogen is 14.0 g/mol.What is the average translational kinetic energy of a nitrogen molecule? The Boltzmann constant is 1.38 × 10^-23 J/K.

A)4.0 ×10²¹ J
B)6.0 ×10²¹ J
C)8.0 ×10²¹ J
D)10 ×10²¹ J
E)12 ×10²¹ J

Question 63

The molecular weight of nitrogen,N₂,is 28 g/mol.What is the rms speed of nitrogen molecules in a cooler at 8.0°C? The Boltzmann constant is 1.38 × 10^-23 J/K and N_A = 6.022 × 10²³ molecules/mol.

A)450 m/s
B)500 m/s
C)550 m/s
D)600 m/s
E)650 m/s

Question 64

A 24.0-L tank contains ideal helium gas at 27°C and a pressure of 22.0 atm.How many moles of gas are in the tank? (R = 8.31 J/mol ∙ K,1 atm = 101 kPa)

A)238 mol
B)138 mol
C)17.5 mol
D)21.4 mol
E)76.0 mol

Question 65

What is the average translational kinetic energy of an ideal gas at The Boltzmann constant is 1.38 × 10^-23 J/K.

A)1.70 x 10^-20 J
B)5.65 x 10^-21 J
C)1.13 x 10^-17 J
D)3.77 x 10^-19 J

Question 66

At what temperature would the root mean square speed of oxygen molecules,O₂,be if oxygen behaves like an ideal gas? The mass of one O₂ molecule is 5.312 × 10^-26 kg,and the Boltzmann constant is 1.38 × 10^-23 J/K.

A)0.251 K
B)2090 K
C)6270 K
D)1.52 × 10²³ K

Question 67

If the temperature of a gas is increased from 20°C to 100°C,by what factor does the rms speed of an ideal molecule change?

A)1.1
B)1.3
C)2.2
D)1.6

Question 68

A flask contains a mixture of argon and neon gases at a stabilized temperature.The root-mean-square speed of the argon gas is determined to be 1.21 km/s.What is the root-mean-square speed of the neon gas? The atomic mass of argon is 39.95 g/mol,and that of neon is 20.18 g/mol.

Question 69

A 5.3 L flask of ideal neon gas (which is monatomic)is at a pressure of 6.0 atm and a temperature of The atomic mass of neon is 20.2 g/mol.What is the mass of the neon gas in the flask.(R = 8.31 J/mol ∙ K,1 atm = 101 kPa,N_A = 6.022 × 10²³ molecules/mol)

A)2.7 × 10^-2
B)1.6 × 10^-2
C)1.3 × 10¹
D)2.7 × 10¹
E)2.7 × 10³

Question 70

A sealed container holds 0.020 moles of ideal nitrogen (N₂)gas,at a pressure of 1.5 atm and a temperature of 290 K.The atomic mass of nitrogen is 14.0 g/mol.How many molecules of nitrogen are in the container? (R = 8.31 J/mol ∙ K,1 atm = 101 kPa)

A)1.5 × 10²¹ mol
B)3.0 × 10²¹ mol
C)6.0 × 10²¹ mol
D)1.2 × 10²² mol
E)2.4 × 10²² mol

Question 71

A 0.50 gas tank holds 3.0 moles of ideal diatomic nitrogen gas at a temperature of The atomic mass of nitrogen is What is the rms speed of the molecules? (The Boltzmann constant is 1.38 × 10^-23 J/K,N_A = 6.022 × 10²³ molecules/mol.)

A)560
B)790
C)390
D)21
E)97

Question 72

At what temperature is the rms speed of hydrogen molecules,H₂,which have a molecular weight of 2.02 g/mole,equal to 2.0 km/s? The Boltzmann constant is 1.38 × 10^-23 J/K and N_A = 6.022 × 10²³ molecules/mol.

A)17°C
B)34°C
C)51°C
D)68°C
E)72°C

Question 73

A 4.2-L flask of ideal neon gas (which is monatomic)is at a pressure of 3.3 atm and a temperature of 450 K.The atomic mass of neon is 20.2 g/mol.How many neon atoms are in the flask? (R = 8.31 J/mol ∙ K,1 atm = 101 kPa,N_A = 6.022 × 10²³ molecules/mol)

A)2.3 × 10²³
B)2.3 × 10²²
C)6.9 × 10²³
D)2.3 × 10²⁵
E)6.9 × 10²²

Question 74

An oxygen molecule,O₂,falls in a vacuum.From what height must it fall so that its translational kinetic energy at the bottom of its fall equals the average translational kinetic energy of an oxygen molecule at 920 K? The mass of one O₂ molecule is 5.312 × 10^-26 kg,and the Boltzmann constant is 1.38 × 10^-23 J/K.Neglect air resistance and assume that g remains constant at 9.8 m/s² throughout the fall of the molecule.

A)49 km
B)12 km
C)24 km
D)37 km
E)5.2 km

Question 75

The rms speed of a certain sample of carbon dioxide molecules,with a molecular weight of 44.0 g/mole,is 396 m/s.What is the rms speed of water vapor molecules,with a molecular weight of 18.0 g/mol,at the same temperature as the carbon dioxide?

A)253 m/s
B)387 m/s
C)421 m/s
D)506 m/s
E)619 m/s

Question 76

What is the average translational kinetic energy of a nitrogen molecule in the air in a room in which the air temperature is 17°C? The Boltzmann constant is 1.38 × 10^-23 J/K.

A)6.01 × 10^-21 J
B)4.00 × 10^-21 J
C)5.00 × 10^-21 J
D)7.00 × 10^-21 J
E)9.00 × 10^-21 J

Question 77

A sealed cylinder fitted with a movable piston contains ideal gas at 27°C,pressure 0.500 × 10⁵ Pa,and volume 1.25 m³.What will be the final temperature if the gas is compressed to 0.800 m³ and the pressure rises to 0.820 × 10⁵ Pa?

A)42°C
B)68°C
C)130°C
D)250°C
E)150°C

Question 78

A 3.9-L volume of ideal neon gas (monatomic)is at a pressure of 5.6 aym and a temperature of The atomic mass of neon is The temperature of the gas is now increased to 430 K and the volume is increased to What is the final pressure of the gas?

A)4.8 atm
B)4.3 atm
C)5.3 atm
D)5.8 atm
E)6.3 atm

Question 79

(a)At what Celsius temperature is the average kinetic energy of a helium gas atom equal to 6.21 × 10^-21 J? The Boltzmann constant is 1.38 × 10^-23 J/K .
(b)What would be the temperature for radon gas?

Question 80

A 0.40- gas tank holds 7.0 moles of ideal diatomic nitrogen gas at a temperature of The atomic mass of nitrogen is What is the pressure of the gas? (R = 8.31 J/mol ∙ K,1 atm = 101 kPa)

A)42 atm
B)37 atm
C)32 atm
D)27 atm
E)22 atm