Deck 5: Gases

Question 1

You have 41.6 g of O₂ gas in a container with twice the volume as one with CO₂ gas.The pressure and temperature of both containers are the same.Calculate the mass of carbon dioxide gas you have in the container.

A)57.2 g
B)0.650 g
C)28.6 g
D)2.60 g
E)none of these

Answer 1

28.6 g

Question 2

A glass column is filled with mercury and inverted in a pool of mercury.The mercury column stabilizes at a height of 729 mm above the pool of mercury.What is the pressure of the atmosphere?

A)1.04 atm
B)0.729 atm
C)0.959 atm
D)456 atm
E)0.639 atm

Answer 2

0.959 atm

Question 3

You have a certain mass of helium gas (He)in a rigid steel container.You add the same mass of neon gas (Ne)to this container.Which of the following best describes what happens? Assume the temperature is constant.

A)The pressure in the container doubles.
B)The pressure in the container increases but does not double.
C)The pressure in the container more than doubles.
D)The volume of the container doubles.
E)The volume of the container more than doubles.

Answer 3

The pressure in the container increases but does not double.

Question 4

Gases generally have

A)low density
B)high density
C)closely packed particles
D)no increase in volume when temperature is increased
E)no decrease in volume when pressure is increased

Question 5

Consider a sample of helium gas in a container fitted with a piston,as pictured below.The piston is frictionless,but has a mass of 10.0 kg.How many of the following processes will cause the piston to move away from the base and decrease the pressure of the gas? Assume ideal behavior.
10.0 kg
$\downarrow$

base $\uarr$
I.heating the helium
II.removing some of the helium from the container
III.turning the container on its side
IV.decreasing the pressure outside the container

A)0
B)1
C)2
D)3
E)4

Question 6

Charles's law states that:

A)Equal amounts of gases occupy the same volume at constant temperature and pressure.
B)The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature.
C)The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure.
D)The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds.
E)The rates of effusion of gases are inversely proportional to the square roots of their molar masses.

Question 7

You are holding two balloons,an orange balloon and a blue balloon.The orange balloon is filled with neon (Ne)gas and the blue balloon is filled with argon (Ar)gas.The orange balloon has twice the volume of the blue balloon.Which of the following best represents the mass ratio of Ne:Ar in the balloons?

A)1:1
B)1:2
C)2:1
D)1:3
E)3:1

Question 8

The local weather forecaster reports that the current barometric pressure is 30.4 inches of mercury.What is the current pressure in atmospheres?

A)1.02 atm
B)10.29 atm
C)1.00 atm
D)4.05 atm
E)910 atm

Question 9

A gas sample is held at constant pressure.The gas occupies 3.62 L of volume when the temperature is 21.6°C.Determine the temperature at which the volume of the gas is 3.42 L.

A)312 K
B)278 K
C)20.4 K
D)295 K
E)552 K

Question 10

Boyle's law states that:

A)Equal amounts of gases occupy the same volume at constant temperature and pressure.
B)The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature.
C)The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure.
D)The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds.
E)The rates of effusion of gases are inversely proportional to the square roots of their molar masses.

Question 11

Consider a sample of gas in a container on a comfortable spring day.The Celsius temperature suddenly doubles,and you transfer the gas to a container with twice the volume of the first container.If the original pressure was 12 atm,what is a good estimate for the new pressure?

A)3 atm
B)5.5 atm
C)6.4 atm
D)12 atm
E)15 atm

Question 12

Which of the following would represent the greatest pressure?

A)0.680 atm
B)517 mmHg
C)11.4 psi
D)62106 Pa
E)14.1 in Hg

Question 13

A physics experiment is conducted at a pressure of 14.4 kPa.What is this pressure in mmHg?

A)18.9 mmHg
B)1.92 mmHg
C) mmHg
D)108 mmHg
E) mmHg

Question 14

Pressure is

A)defined as the mass that an object exerts when at rest
B)measured in Newtons
C)defined as the number of moles of substance divided by the mass of the substance
D)defined as the force per unit area
E)measured in grams

Question 15

A balloon has a volume of 2.32 liters at 24.0°C.The balloon is heated to 48.0°C.Calculate the new volume of the balloon.

A)2.32 L
B)2.51 L
C)2.15 L
D)4.64 L
E)1.16 L

Question 16

Gaseous chlorine is held in two separate containers at identical temperature and pressure.The volume of container 1 is 1.30 L,and it contains 6.70 mol of the gas.The volume of container 2 is 2.33 L.How many moles of the gas are in container 2?

A)12.0 mol
B)20.3 mol
C)0.452 mol
D)3.74 mol
E)none of these

Question 17

The SI unit of pressure is the

A)ampere
B)kilojoule
C)newton
D)gram
E)pascal

Question 18

The air pressure in the inner tube of a tire on a typical racing bike is held at a pressure of about 112 psi.Convert this pressure to atm.

A)0.147 atm
B)7.62 atm
C)0.112 atm
D)0.131 atm
E)112 atm

Question 19

Avogadro's law states that:

A)Equal amounts of gases occupy the same volume at constant temperature and pressure.
B)The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature.
C)The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure.
D)The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds.
E)The rates of effusion of gases are inversely proportional to the square roots of their molar masses.

Question 20

Body temperature is about 309 K.On a cold day,what volume of air at 276 K must a person with a lung capacity of 2.2 L breathe in to fill the lungs?

A)2.46 L
B)1.97 L
C)2.08 L
D)3.93 L
E)none of these

Question 21

Which conditions of P,T,and n,respectively,are most ideal?

A)high P,high T,high n
B)low P,low T,low n
C)high P,low T,high n
D)low P,high T,high n
E)low P,high T,low n

Question 22

You have two samples of the same gas in the same size container,with the same pressure.The gas in the first container has a Kelvin temperature four times that of the gas in the other container.
The ratio of the average velocity of particles in the first container compared to that in the second is

A)1:1
B)4:1
C)1:4
D)2:1
E)1:2

Question 23

You have two samples of the same gas in the same size container,with the same pressure.The gas in the first container has a Kelvin temperature four times that of the gas in the other container.
The ratio of the number of moles of gas in the first container compared to that in the second is

A)1:1
B)4:1
C)1:4
D)2:1
E)1:2

Question 24

A gas sample is heated from -20.0°C to 57.0°C and the volume is increased from 2.00 L to 4.50 L.If the initial pressure is 0.140 atm,what is the final pressure?

A)0.0477 atm
B)-0.177 atm
C)0.411 atm
D)0.242 atm
E)0.0811 atm

Question 25

You fill a balloon with 2.50 moles of gas at 22°C at a pressure of 1.62 atm.What is the volume of the balloon?

A)15.7 L
B)98.0 L
C)37.4 L
D)2.79 L
E)22.4 L

Question 26

A sample of 35.1 g of methane gas has a volume of 3.11 L at a pressure of 2.70 atm.Calculate the temperature.

A)2.92 K
B)46.8 K
C)320 K
D)32.4 K
E)35.0 K

Question 27

A 41.1-g sample of Ne gas exerts a certain pressure in a container of fixed volume.What mass of Ar is required to exert half the pressure at the same conditions of volume and temperature?

A)81.4 g Ar
B)1.02 g Ar
C)163 g Ar
D)821 g Ar
E)40.7 g Ar

Question 28

Mercury vapor contains Hg atoms.What is the volume of 201 g of mercury vapor at 822 K and 0.512 atm?

A)132 L
B) L
C)175 L
D)34.5 L
E)17.3 L

Question 29

Consider three 1-L flasks at STP.Flask A contains NH₃ gas,flask B contains NO₂ gas,and flask C contains N₂ gas.
In which flask do the molecules have the highest average velocity?

A)Flask A
B)Flask B
C)Flask C
D)All are the same.
E)More information is needed to answer this.

Question 30

A 3.60-L sample of carbon monoxide is collected at 55°C and 0.869 atm.What volume will the gas occupy at 1.05 atm and 25°C?

A)1.35 L
B)3.95 L
C)2.71 L
D)3.28 L
E)none of these

Question 31

An automobile tire is filled with air at a pressure of 27.0 lb/in² at 25°C.A cold front moves through and the temperature drops to 5°C.Assuming no change in volume,what is the new tire pressure?

A)5.40 lb/in²
B)25.2 lb/in²
C)28.9 lb/in²
D)135 lb/in²
E)4.63 lb/in²

Question 32

A sample of oxygen gas has a volume of 1.72 L at 27°C and 800.0 torr.How many oxygen molecules does it contain?

A)
B)
C)
D)
E)none of these

Question 33

Three 1.00-L flasks at 25°C and 725 torr contain the gases CH₄ (flask A),CO₂ (flask B),and C₂H₆ (flask C).
In which single flask do the molecules have the greatest mass,the greatest average velocity,and the highest kinetic energy?

A)Flask A
B)Flask B
C)Flask C
D)All are the same.
E)No one flask has all these.

Question 34

You are holding four identical balloons each containing 10.0 g of a different gas.The balloon containing which gas is the largest balloon?

A)H₂
B)He
C)Ne
D)O₂
E)All have the same volume.

Question 35

Three 1.00-L flasks at 25°C and 725 torr contain the gases CH₄ (flask A),CO₂ (flask B),and C₂H₆ (flask C).
In which flask is there 0.039 mol of gas?

A)Flask A
B)Flask B
C)Flask C
D)all
E)none

Question 36

A sample of helium gas occupies 14.7 L at 23°C and 0.956 atm.What volume will it occupy at 40°C and 1.20 atm?

A)19.5 L
B)20.4 L
C)11.1 L
D)12.4 L
E)14.9 L

Question 37

What volume is occupied by 21.0 g of methane (CH₄)at 27°C and 1.25 atm?

A)37.2 L
B)25.8 L
C)2.32 L
D) L
E)not enough data to calculate

Question 38

Consider three 1-L flasks at STP.Flask A contains NH₃ gas,flask B contains NO₂ gas,and flask C contains N₂ gas.
Which contains the largest number of molecules?

A)Flask A
B)Flask B
C)Flask C
D)All are the same.
E)More information is need to answer this.

Question 39

A 7.94-g piece of solid CO₂ (dry ice)is allowed to sublime in a balloon.The final volume of the balloon is 1.00 L at 301 K.What is the pressure of the gas?

A)4.46 atm
B) atm
C)3.11 atm
D)0.224 atm
E)none of these

Question 40

Consider three 1-L flasks at STP.Flask A contains NH₃ gas,flask B contains NO₂ gas,and flask C contains N₂ gas.
In which flask are the molecules least polar and therefore most ideal in behavior?

A)Flask A
B)Flask B
C)Flask C
D)All are the same.
E)More information is needed to answer this.

Question 41

A sample of gas is in a 50.0-mL container at a pressure of 645 torr and a temperature of 25°C.The entire sample is heated to a temperature of 35°C and transferred to a new container whose volume is 98.7 mL.The pressure of the gas in the second container is about:

A)457 torr
B)316 torr
C) torr
D)65 torr
E)338 torr

Question 42

Four identical 1.0-L flasks contain the gases He,Cl₂,CH₄,and NH₃,each at 0°C and 1 atm pressure.
For which gas do the molecules have the highest average velocity?

A)He
B)Cl₂
C)CH₄
D)NH₃
E)all gases the same

Question 43

Which of the following is the best qualitative graph of P versus molar mass of a 1-g sample of different gases at constant volume and temperature?

A)
B)
C)
D)
E)none of these

Question 44

It is found that 250.mL of a gas at STP has a mass of 0.700 g.What is the molar mass?

A)62.7 g/mol
B)2.80 g/mol
C)15.9 g/mol
D)11.2 g/mol
E)128 g/mol

Question 45

Four identical 1.0-L flasks contain the gases He,Cl₂,CH₄,and NH₃,each at 0°C and 1 atm pressure.
Which gas sample has the greatest number of molecules?

A)He
B)Cl₂
C)CH₄
D)NH₃
E)all gases the same

Question 46

Gaseous reacts with according to the following equation: What volume of oxygen gas at STP is needed to react with 5.75 mol of ?

A)17.3 L
B)42.9 L
C) L
D) L
E)Not enough information is given to solve the problem.

Question 47

Four identical 1.0-L flasks contain the gases He,Cl₂,CH₄,and NH₃,each at 0°C and 1 atm pressure.
Which gas has the highest density?

A)He
B)Cl₂
C)CH₄
D)NH₃
E)all gases the same

Question 48

Four identical 1.0-L flasks contain the gases He,Cl₂,CH₄,and NH₃,each at 0°C and 1 atm pressure.
For which gas do the molecules have the smallest average kinetic energy?

A)He
B)Cl₂
C)CH₄
D)NH₃
E)all gases the same

Question 49

Given reaction 2NH₃(g)+ 3Cl₂(g) $\to$ N₂(g)+ 6HCl(g),you react 5.0 L of NH₃ with 5.0 L of Cl₂ measured at the same conditions in a closed container.Calculate the ratio of pressures in the container (P_final/P_initial).

A)0.75
B)1.00
C)1.33
D)1.50
E)none of these

Question 50

When 0.72 g of a liquid is vaporized at 110°C and 0.967 atm,the gas occupies a volume of 0.559 L.The empirical formula of the gas is CH₂.What is the molecular formula of the gas?

A)CH₂
B)C₂H₄
C)C₃H₆
D)C₄H₈
E)none of these

Question 51

You carry out the reaction represented by the following balanced equation: N₂(g)+ 3H₂(g) $\to$ 2NH₃(g)
You add an equal number of moles of nitrogen and hydrogen gases in a balloon.The volume of the balloon is 1.00 L before any reaction occurs.Determine the volume of the balloon after the reaction is complete.Assume constant temperature.

A)0.330 L
B)0.670 L
C)1.00 L
D)1.50 L
E)3.00 L

Question 52

Given a cylinder of fixed volume filled with 1 mol of argon gas,which of the following is correct? (Assume all gases obey the ideal gas law. )

A)If the temperature of the cylinder is changed from 25°C to 50°C,the pressure inside the cylinder will double.
B)If a second mole of argon is added to the cylinder,the ratio T/P would remain constant.
C)A cylinder of identical volume filled with the same pressure of helium must contain more atoms of gas because He has a smaller atomic radius than argon.
D)Two of the above.
E)None of the above.

Question 53

Argon has a density of 1.78 g/L at STP.How many of the following gases have a density at STP greater than that of argon? Cl₂
He
NH₃
NO₂

A)0
B)1
C)2
D)3
E)4

Question 54

The temperature of a specific amount of gas in a sealed container changes from 20.0°C to 40.0°C.If the volume remains constant,the pressure will change from 755 mmHg to

A)1510 mmHg
B)707 mmHg
C)378 mmHg
D)807 mmHg
E)755 mmHg

Question 55

The bag is emptied and refilled,successively,with gases X and Y,this time at 1 atm pressure and a temperature 30°C higher.Assume that the volume of the bag is the same as before.Which one of the following statements is wrong?

A)The full bag contains fewer molecules of each gas than it did at 0.0°C.
B)The ratio of the density of gas Y to the density of gas X is the same as at 0.0°C.
C)The molar masses of the two gases are the same as they were at 0.0°C.
D)The mass of each gas filling the bag is now 303/273 times the mass held at 0.0°C.
E)The average velocity of the molecules of gas X at 30°C is higher than it was at 0.0°C.

Question 56

Four identical 1.0-L flasks contain the gases He,Cl₂,CH₄,and NH₃,each at 0°C and 1 atm pressure.
For which gas are the collisions elastic?

A)He
B)Cl₂
C)CH₄
D)NH₃
E)all gases the same

Question 57

Four identical 1.0-L flasks contain the gases He,Cl₂,CH₄,and NH₃,each at 0°C and 1 atm pressure.
For which gas are the molecules diatomic?

A)He
B)Cl₂
C)CH₄
D)NH₃
E)all gases the same

Question 58

Given reaction N₂ + 3H₂ $\to$ 2NH₃,you mix 1 mol each of nitrogen and hydrogen gases under the same conditions in a container fitted with a piston.Calculate the ratio of volumes of the container (V_final/V_initial).

A)0.67
B)1.00
C)1.33
D)1.50
E)none of these

Question 59

A plastic bag is weighed and then filled successively with two gases,X and Y.The following data are gathered:
Temperature: 0.0°C (273 K)
Pressure: 1.00 atmosphere
Mass of empty bag: 20.77 g
Mass of bag filled with gas X: 24.97 g
Mass of 1.12 liters of air at conditions given: 1.30 g
Volume of bag: 1.12 liter
Molar volume at STP: 22.4 liters
The mass of 1.12 liters of gas Y is found to be 6.23 g.The density of gas Y is

A)10.6 g/L
B)5.56 g/L
C)15.6 g/L
D)0.200 g/L
E)0.180 g/L

Question 60

A 3.54 gram sample of a certain diatomic gas occupies a volume of 3.30-L at 1.00 atm and a temperature of 45°C.Identify this gas.

A)
B)
C)
D)
E)

Question 61

At 1000°C and 10.torr,the density of a certain element in the gaseous state is .The element is:

A)F
B)He
C)Na
D)Zn
E)Hg

Question 62

An excess of sodium hydroxide is treated with 26.5 L of dry hydrogen chloride gas measured at STP.What is the mass of sodium chloride formed?

A)1.55 kg
B)1.69 g
C)0.138 kg
D)69.1 g
E)13.3 g

Question 63

Air has an average molar mass of 29.0 g/mol.The density of air at 0.97 atm and 30.0°C is:

A)29.0 g/L
B)39.0 g/mL
C)1.13 g/L
D)1.35 g/mL
E)11.4 g/L

Question 64

The purity of a sample containing zinc and weighing 0.312 g is determined by measuring the amount of hydrogen formed when the sample reacts with an excess of hydrochloric acid.The determination shows the sample to be 84.0% zinc.What amount of hydrogen (measured at STP)was obtained?

A) L
B) g
C) mole
D) molecules
E) atoms

Question 65

A 1.00-g sample of a gaseous compound of boron and hydrogen occupies 0.820 L at 1.00 atm and 3°C.What is the molecular formula for the compound?

A)BH₃
B)B₂H₆
C)B₄H₁₀
D)B₃H₁₂
E)B₅H₁₄

Question 66

Into a 2.22-liter container at 25°C are placed 1.23 moles of O₂ gas and 3.20 moles of solid C (graphite).If the carbon and oxygen react completely to form CO(g),what will be the final pressure in the container at 25°C?

A)27.1 atm
B)13.5 atm
C)2.27 atm
D)35.2 atm
E)none of these

Question 67

Standard pressure for gases is

A)0 atm
B)1 atm
C)100 atm
D)dependent upon temperature
E)none of the above

Question 68

One way to isolate metals from their ores is to react the metal oxide with carbon as shown in the following reaction: If 34.08 g of a metal oxide reacted with excess carbon and 4.37 L of CO₂ formed at 100°C and 1.50 atm,what is the identity of the metal?

A)Hg
B)Mg
C)Cu
D)Cd
E)Zn

Question 69

A 3.31-g sample of lead nitrate, ,molar mass = 331 g/mol,is heated in an evacuated cylinder with a volume of 2.37 L.The salt decomposes when heated,according to the equation: Assuming complete decomposition,what is the pressure in the cylinder after decomposition and cooling to a temperature of 300.K? Assume the takes up negligible volume.

A)0.260 atm
B)0.208 atm
C)0.0519 atm
D)0.364 atm
E)34.4 atm

Question 70

What volume of carbon dioxide measured at STP will be formed by the reaction of 1.47 mol of oxygen with 0.900 mol of ethyl alcohol,CH₃CH₂OH?

A)40.3 mL
B)22.0 L
C)32.9 L
D)49.4 L
E)0.980 L

Question 71

If M is the molar mass,R the gas constant,T the temperature,and P its pressure,which of the following expressions represents the density of a gas?

A)
B)
C)
D)
E)

Question 72

The standard temperature for gases is

A)100°C
B)0°C
C)32°C
D)212°F
E)0°F

Question 73

What volume does 40.5 g of N₂ occupy at STP?

A)64.8 L
B)1.81 L
C)32.4 L
D)50.7 L
E)none of these

Question 74

What volume of measured at STP is produced by the combustion of 6.27 g of natural gas according to the following equation?

A)8.76 L
B)17.5 L
C)4.38 L
D)19.1 L
E)3.14 L

Question 75

A mixture is prepared from 15.0 L of ammonia and 15.0 L chlorine measured at the same conditions;these compounds react according to the following equation: When the reaction is completed,what is the volume of each gas (NH₃,Cl₂,N₂,and HCl,respectively)? Assume the final volumes are measured under identical conditions.

A)0.00 L,5.00 L,7.50 L,45.0 L
B)5.00 L,0.00 L,5.00 L,30.0 L
C)0.00 L,0.00 L,7.50 L,45.0 L
D)0.00 L,0.00 L,5.00 L,30.0 L
E)0.00 L,10.0 L,15.0 L,90.0 L

Question 76

Calculate the density of nitrogen at STP.

A)0.312 g/L
B)0.625 g/L
C)0.800 g/L
D)1.25 g/L
E)1.60 g/L

Question 77

Given the equation: A 3.00-g sample of KClO₃ is decomposed and the oxygen at 24.0°C and 0.717 atm is collected.What volume of oxygen gas will be collected assuming 100% yield?

A) mL
B) mL
C) mL
D) mL
E)none of these

Question 78

A mixture of KCl and KClO₃ weighing 1.34 grams was heated;the dry O₂ generated occupied 143 mL at STP.What percent of the original mixture was KClO₃,which decomposes as follows:

A)38.9%
B)58.4%
C)87.6%
D)10.7%
E)23.7%

Question 79

If a 17.90-g sample of a gas occupies 10.0 L at STP,what is the molar mass of the gas at 125°C?

A)5.48 g/mol
B)40.1 g/mol
C)18.4 g/mol
D)58.5 g/mol
E)Not enough information is given.

Question 80

Calcium hydride combines with water according to the equation: Beginning with 84.0 g of CaH₂ and 42.0 g of H₂O,what volume of H₂ will be produced at 273 K and a pressure of 1327 torr?

A)29.9 L
B)15.0 L
C) L
D)25.7 L
E)none of these