Deck 17: Phases and Phase Changes

Question 1

A large 75-kg lighting fixture can be hung from wires of identical size and shape made of aluminum,brass,or copper.The values of Young's modulus for these metals are 0.70 × 10¹¹ Pa (aluminum),0.91 × 10¹¹ (brass),and 1.1 × 10¹¹ (copper).Which wire would stretch the least distance?

A)aluminum
B)brass
C)copper
D)They will all stretch the same distance.

Answer 1

copper

Question 2

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.

Answer 2

Both gases have the same number of molecules.
Both gases have the same average kinetic energy per molecule.

Question 3

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.

Answer 3

2v.

Question 4

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 5

Which of the following are SI units of Young's modulus? (There could be more than one correct choice. )

A)N/m ∙ s²
B)kg/m²
C)kg ∙ m/s²
D)kg/m ∙ s²
E)kg ∙ m²/s²

Question 6

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 7

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 8

A 25-kg piece of equipment can be hung by steel wires of length 1.00 m,2.00 m,or 3.00 m.If all the wires have the same diameter,which one will stretch the greatest distance?

A)the 1.00-m wire
B)the 2.00-m wire
C)the 3.00-m wire
D)They will all stretch by the same distance.

Question 9

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 10

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 11

The figure shows a graph of the temperature of a pure substance as a function of time as heat is added to it at a constant rate in a closed container.If L_F is the latent heat of fusion of this substance and L_V is its latent heat of vaporization,what is the value of the ratio L_V/L_F?

A)5.0
B)4.5
C)7.2
D)3.5
E)1.5

Question 12

How much heat must be removed from 456 g of water at 25.0°C to change it into ice at -10.0°C? The specific heat of ice is 2090 J/kg ∙ K,the latent heat of fusion of water is 33.5 × 10⁴ J/kg,and the specific heat of water is 4186 J/kg ∙ K.

A)105 kJ
B)153 kJ
C)57.3 kJ
D)47.7 kJ
E)210 kJ

Question 13

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 14

Two wires are made out of the same metal,but one wire is twice as long as the other wire.Which wire will have the greatest elastic modulus?

A)the shorter wire
B)the longer wire
C)It will be the same for both wires.

Question 15

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

Question 16

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.

Question 17

A 25-kg piece of equipment can be hung by steel wires of length 1.00 m,2.00 m,or 3.00 m.If all the wires have the same diameter,which one will stretch the greatest percent?

A)the 1.00-m wire
B)the 2.00-m wire
C)the 3.00-m wire
D)They will all stretch by the same percent.

Question 18

A runner generates 1260 W of thermal energy.If this heat has to be removed only by evaporation,how much water does this runner lose in 15 minutes of running? The latent heat of vaporization of water is
.

A)50 g
B)500 g
C)35 g
D)350 g
E)40 g

Question 19

As one stretches a metal wire,which condition is reached first?

A)the elastic limit
B)the breaking point
C)the proportional limit

Question 20

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 21

When a sample of water at 0.0°C is cooled to -36.0°C and freezes in the process,935,000 kJ of heat is liberated.What is the mass of this sample of water? For water L_F = 334,000 J/kg,L_V = 2.256 × 10⁶ J/kg,and the specific heat of ice is 2050 J/kg ∙ °C.

A)2290 kg
B)1145 kg
C)2800 kg
D)12,700 kg

Question 22

A 40.0-g block of ice at -15.00°C is dropped into a calorimeter (of negligible heat capacity)containing water at 15.00°C.When equilibrium is reached,the final temperature is 8.00°C.How much water did the calorimeter contain initially? The specific heat of ice is 2090 J/kg ∙ K,that of water is 4186 J/kg ∙ K,and the latent heat of fusion of water is 33.5 × 10⁴ J/kg.

A)302 g
B)345 g
C)405 g
D)546 g
E)634 g

Question 23

A person makes iced tea by adding ice to 1.8 kg of hot tea,initially at 80°C.How many kilograms of ice,initially at 0°C,are required to bring the mixture to 10°C? The specific heat of water (and tea)is 4186 J/kg ∙ K,and the latent heat of fusion of ice is 3.34 × 10⁵ J/kg.

A)1.0 kg
B)1.2 kg
C)1.4 kg
D)1.7 kg

Question 24

A metal has a latent heat of fusion of 2.32 × 10⁴ J/kg,a specific heat of 128 J/kg ∙ K,and a melting point of 228°C.A 30-g pellet of this metal at 16°C hits a solid wall and comes to a complete stop.What would the speed of the pellet have to be in order for it to melt completely when it hits the wall,assuming that all of its kinetic energy is transformed into heat within the pellet?

A)207 m/s
B)215 m/s
C)232 m/s
D)273 m/s
E)317 m/s

Question 25

An 920-g piece of iron at 100°C is dropped into a calorimeter of negligible heat capacity containing 50 g of ice at 0°C and 92 g of water,also at 0°C.What is the final temperature of the system? The specific heat of iron is 448 J/kg ∙ K,that of water is 4186 J/kg ∙ K,and the latent heat of fusion of water is 33.5 × 10⁴ J/kg.

A)0°C
B)11°C
C)14°C
D)24°C
E)32°C

Question 26

A .20-kg ice cube at 0.0°C has sufficient heat added to it to cause total melting,and the resulting water is heated to 70.0 °C. How much heat is added? For water L_F = 334,000 J/kg,L_V = 2.256 × 10⁶ J/kg,the c = 4.186 x 10³ J/kg ∙C.

A)130 kJ
B)14,000 kJ
C)81 kJ
D)59 kJ

Question 27

A 2,294-kg sample of water at 0° C is cooled to -36 ° C, And freezes in the process.How much heat is liberated? For water L_F = 334,000 J/kg and L_V = 2.256 × 10⁶ J/kg.The specific heat of ice is 2050 J/kg ∙ K.

A)935,000 kJ
B)597,000 kJ
C)1,110,000 kJ
D)334,000 kJ

Question 28

How much heat must be added to a 8.0-kg block of ice at -8°C to change it to water at
The specific heat of ice is 2050 J/kg ∙ °C,the specific heat of water is 4186 J/kg ∙ °C,the latent heat of fusion of ice is 334,000 J/kg,and 1 cal = 4.186 J.

A)780 kcal
B)140 kcal
C)180 kcal
D)810 kcal
E)730 kcal

Question 29

A 35-g block of ice at -14°C is dropped into a calorimeter (of negligible heat capacity)containing 400 g of water at 0°C.When the system reaches equilibrium,how much ice is left in the calorimeter? The specific heat of ice is 2090 J/kg ∙ K,that of water is 4186 J/kg ∙ K,and the latent heat of fusion of water is 33.5 × 10⁴ J/kg.

A)32 g
B)33 g
C)35 g
D)38 g
E)41 g

Question 30

A 44.0-g block of ice at -15.0°C is dropped into a calorimeter (of negligible heat capacity)containing 100g. Of water at 5.0°C.When equilibrium is reached,how much of the ice will have melted? The specific heat of ice is 2090 J/kg ∙ K,that of water is 4186 J/kg ∙ K,and the latent heat of fusion of water is 33.5 × 10⁴ J/kg.

A)2.1 g
B)21 g
C)5.2 g
D)52 g
E)4.4 g

Question 31

A substance has a melting point of 20°C and a heat of fusion of 3.4 ×
J/kg.The boiling point is
And the heat of vaporization is
At a pressure of one atmosphere.The specific heats for the solid,liquid,and gaseous phases are 600 J/kg ∙ K (solid),1000 J/kg ∙ K (liquid),and 400 J/kg ∙ K (gaseous).How much heat is required to raise the temperature of
Of this substance from
To
At a pressure of one atmosphere?

A)260 kJ
B)190 kJ
C)230 kJ
D)92 kJ
E)320 kJ

Question 32

A 45.0-kg sample of ice is at 0.00° C.How much heat is needed to melt it? For water L_F = 334,000 J/kg and L_V = 2.256 × 10⁶ J/kg.

A)1.50 × 10⁴ _kJ
B)4.10 × 10⁶ _kJ
C)0.00 kJ
D)1.02 × 10⁵ _kJ

Question 33

A 400-g block of iron at 400°C is dropped into a calorimeter (of negligible heat capacity)containing 60 g of water at 30°C.How much steam is produced? The latent heat of vaporization of water is 22.6 × 10⁵ J/kg and its specific heat capacity is 4186 J/kg ∙ K.The average specific heat of iron over this temperature range is 560 J/kg ∙ K.

A)22 g
B)33 g
C)42 g
D)54 g
E)59 g

Question 34

A substance has a melting point of 20°C and a heat of fusion of
The boiling point is
And the heat of vaporization is
At a pressure of one atmosphere.The specific heats for the solid,liquid,and gaseous phases are 600 J/kg ∙ K (solid),1000 J/kg ∙ K (liquid),and 400 J/kg ∙ K (gaseous).How much heat is given up by
Of this substance when it is cooled from 170°C to 86°C at a pressure of one atmosphere?

A)400 kJ
B)200 kJ
C)300 kJ
D)440 kJ
E)640 kJ

Question 35

If you add 700 kJ of heat to 700 g of water originally at 70.0°C,how much water is left in the container? The latent heat of vaporization of water is 22.6 ×
J/kg,and its specific heat capacity is
.

A)429 g
B)258 g
C)340 g
D)600 g
E)none

Question 36

Solar houses use a variety of energy storage devices to retain the heat absorbed during the day so that it can be released during the night.Suppose that you were to use a device of this kind to produce steam at 100°C during the day,and then allow the steam to cool to 0°C and freeze during the night.How many kilograms of water would be needed to store 20.0 kWh of energy in this way? The latent heat of vaporization of water is 22.6 × 10⁵ J/kg,the latent heat of fusion of water is 33.5 × 10⁴ J/kg,and the specific heat capacity of water is 4186 J/kg ∙ K.

A)12.4 kg
B)23.9 kg
C)35.7 kg
D)42.6 kg
E)54.2 kg

Question 37

The melting point of aluminum is 660°C,its latent heat of fusion is 4.00 × 10⁵ J/kg,and its specific heat is 900J/kg ∙ K.How much heat must be added to 500 g of aluminum originally at 27°C to completely melt it?

A)485 kJ
B)395 kJ
C)273 kJ
D)147 kJ
E)14 kJ

Question 38

If you add 1.33 MJ of heat to 500 g of water at 50°C in a sealed container,what is the final temperature of the steam? The latent heat of vaporization of water is 22.6 × 10⁵ J/kg,the specific heat of steam is 2010 J/kg ∙ K,and the specific heat of water is 4186 J/kg ∙ K.

A)100°C
B)112°C
C)123°C
D)147°C
E)195°C

Question 39

Heat is added to a 3.0 kg piece of ice at a rate of
How long will it take for the ice at 0.0° C to melt? For water L_F = 334,000 J/kg and L_V = 2.246 × 10⁶ J/kg.

A)1.6 s
B)640,000 s
C)0.0 s
D)1,000 s

Question 40

A 771.0-kg copper bar is put into a smelter for melting.The initial temperature of the copper is 300.0 K.How much heat must the smelter produce to completely melt the copper bar? The specific heat for copper is 386 J/kg ∙ K,the heat of fusion for copper is 205,000 J/kg,and its melting point is 1357 K.

A)4.73 × 10⁵ _kJ
B)3.15 × 10¹¹ _kJ
C)3.15 × 10⁸ _kJ
D)5.62 × 10⁵ _kJ

Question 41

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 × 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 42

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 43

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 44

Two experimental runs are performed to determine the calorimetric properties of an alcohol which has a melting point of -10° C.In the first run,a 200-g cube of frozen alcohol,at the melting point,is added to 300 g of water at 20°C in a styrofoam container.When thermal equilibrium is reached,the alcohol-water solution is at a temperature of 5°C.In the second run,an identical cube of alcohol is added to 500 g of water at 20°C and the temperature at thermal equilibrium is 10°C.The specific heat capacity of water is 4190 J/kg ∙ K.Assume no heat is exchanged with the styrofoam container and the surroundings.What is the specific heat capacity of the alcohol?

A)1700 J/kg ∙ K
B)1900 J/kg ∙ K
C)2100 J/kg ∙ K
D)2300 J/kg ∙ K
E)2500 J/kg ∙ K

Question 45

In an experiment to measure the thermal conductivity of a certain material,a slab of material 10.0 mm thick separates a steam chamber from a block of ice with a square cross-section with dimensions 8.00 cm × 8.00 cm.After 5.00 min of running the experiment,64.0 g of ice have melted.What is the thermal conductivity of this material? The latent heat of fusion of water is 33.5 × 10⁴ J/kg,the latent heat of vaporization of water is 2.256 × 10⁶ J/kg,and both the ice and water are under 1.00 atm of pressure.

A)0.130 W/m ∙ K
B)0.250 W/m ∙ K
C)0.440 W/m ∙ K
D)0.620 W/m ∙ K
E)1.12 W/m ∙ K

Question 46

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 47

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 48

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 49

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 50

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 51

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 52

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 53

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 54

A 360-g metal container,insulated on the outside,holds 180.0 g of water in thermal equilibrium at 22.0°C.A 24.0-g ice cube,at the melting point,is dropped into the water,and when thermal equilibrium is reached the temperature is 15.0°C.Assume there is no heat exchange with the surroundings.For water,the specific heat capacity is 4190 J/kg ∙ K and the heat of fusion is 3.34 × 10⁵ J/kg.What is the specific heat capacity of the metal of the container?

A)1700 J/kg ∙ K
B)970 J/kg ∙ K
C)2300 J/kg ∙ K
D)2800 J/kg ∙ K
E)3300 J/kg ∙ K

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

Two experimental runs are performed to determine the calorimetric properties of an alcohol which has a melting point of -10.0° C.In the first run,a 200-g cube of frozen alcohol,at the melting point,is added to 300 g of water at 20.0°C in a styrofoam container.When thermal equilibrium is reached,the alcohol-water solution is at a temperature of 5.0°C.In the second run,an identical cube of alcohol is added to 500 g of water at 20.0°C and the temperature at thermal equilibrium is 10.0°C.The specific heat capacity of water is 4190 J/kg ∙ K.Assume no heat is exchanged with the styrofoam container and the surroundings.What is the heat of fusion of the alcohol?

A)5.5 × 10⁴ J/kg
B)6.3 × 10⁴ J/kg
C)7.1 × 10⁴ J/kg
D)7.9 × 10⁴ J/kg
E)8.7 × 10⁴ J/kg

Question 57

A 5.3 L flask of ideal neon gas (which is monatomic)is at a pressure of 6.0 atm and a temperature of 290 K. 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 58

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 59

How many moles are there in 2.00 kg of copper? The atomic weight 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 60

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 61

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 62

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 63

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 × 10^-20 J
B)5.65 × 10^-21 J
C)1.13 × 10^-17 J
D)3.77 × 10^-19 J

Question 64

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 65

Dust particles in a grain elevator frequently have masses of the order of 1.0 × 10^-9 kg.If,to a first approximation,we model the dust particles as an ideal gas,what would be the rms speed of such a particle in air at 27°C? The Boltzmann constant is 1.38 × 10^-23 J/K .

A)3.5 × 10^-6 m/s
B)5.6 × 10^-5 m/s
C)7.8 × 10^-4 m/s
D)5.2 × 10^-3 m/s
E)4.9 × 10^-2 m/s

Question 66

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 67

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 68

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 69

A 3.9-L volume of ideal neon gas (monatomic)is at a pressure of 5.6 aym and a temperature of 330 K. The atomic mass of neon is 20.2 g/mol. The temperature of the gas is now increased to 430 K and the volume is increased to 5.9 L.
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 70

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)2,090 K
C)6,270 K
D)1.52 × 10²³ K

Question 71

If the temperature of an ideal gas is increased from 20°C to 40°C,by what percent does the speed of the molecules increase?

A)3%
B)30%
C)70%
D)100%

Question 72

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 73

At what temperature would the root-mean-square speed of hydrogen,H₂,molecules equal 11.2 km/s (the earth's escape speed)? The mass of a hydrogen atom is 1.67 × 10^-27 kg,and the Boltzmann constant is 1.38 × 10^-23 J/K.

A)1.01 × 10² K
B)1.01 × 10⁴ K
C)1.01 × 10⁶ K
D)1.01 × 10⁸ K

Question 74

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 75

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 76

A 0.50 m³ Gas tank holds 3.0 moles of ideal diatomic nitrogen gas at a temperature of 350 K. The atomic mass of nitrogen is 14.0 g/mol. 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 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 0.40- m³. Gas tank holds 7.0 moles of ideal diatomic nitrogen gas at a temperature of 290 K. The atomic mass of nitrogen is 14.0 g/mol. 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

Question 79

If an ideal gas molecule has a speed of 0.50 km/s at 20°C,what is its speed at 80°C?

A)500 m/s
B)550 m/s
C)1000 m/s
D)2000 m/s

Question 80

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