Deck 5: The Properties of Gases

Question 1

A pressure of 2.50* 10⁵ kg.m ^{- 1}.s ^{- 2} corresponds to

A)1.00 atm
B)760 mmHg
C)253 kPa
D)2.50 * 10⁵ Torr
E)2.50 Pa

Answer 1

253 kPa

Question 2

The height of water in a water barometer is 883 cm at 20 $\degree$ C.The density of water at 20 $\degree$ C is 0.998 g.cm ^{- 3}.What is the pressure?

A)88.3 kPa
B)8.81*10³ Pa
C)101 kPa
D)8.64 *10³ Pa
E)86.4 kPa

Answer 2

86.4 kPa

Question 3

What is the density of helium gas at 750 kPa and 25 $\degree$ C?

A)2.42 g.L ^{- 1}
B)1.21 g.L ^{- 1}
C)0.605 g.L ^{- 1}
D)0.161 g.L ^{- 1}
E)0.0120 g.L ^{- 1}

Answer 3

1.21 g.L ^{- 1}

Question 4

All of the following elements are gases at room temperature and atmospheric pressure except

A)Rn
B)F
C)Br
D)N
E)Cl

Question 5

What is the pressure inside a system when the system-side column in an open mercury manometer is 75.0 mm lower than the atmosphere side when the atmospheric pressure is 735 mmHg?

A)820 kPa
B)10.0 kPa
C)88.0 kPa
D)75 kPa
E)108 kPa

Question 6

The height of mercury in a barometer is 77.5 cm.What height would water reach in a water barometer? The density of mercury is 13.6 g.cm ^{- 3} and that of water 1.00 g.cm ^{- 3}.The temperature is constant.

A)175 cm
B)55.9 cm
C)760 cm
D)5.70 cm
E)1.05 *10³ cm

Question 7

A badly tuned automobile engine can release about 50 moles of carbon dioxide per hour.At 35 $\degree$ C,what volume of carbon dioxide is released in a six-hour period if the atmospheric pressure is 740 Torr?

A)7.9 * 10⁵ L
B)7.8 * 10³ L
C)1.3 *10³ L
D)10 L
E)1.3 *10⁵ L

Question 8

What is the density of xenon gas at 750 kPa and 25 $\degree$ C?

A)5.30 g.L ^{- 1}
B)0.392 g.L ^{- 1}
C)39.7 g.L ^{- 1}
D)79.5 g.L ^{- 1}
E)19.9 g.L ^{- 1}

Question 9

The number of molecules in 44.8 L of nitrogen at exactly 0 $\degree$ C and 3.00 atm is

A)1.20 * 10²⁴
B)3.61 * 10²⁴
C)3.61 * 10^-23
D)2.01 *10²³
E)18.0*10 ^{- 23}

Question 10

If 2.00 moles of an ideal gas at STP is subjected to a new pressure of 24.7 kPa,the volume of the gas will become

A)8.20 L
B)22.4 L
C)11.2 L
D)184 L
E)91.9 L

Question 11

A sample of gas with a volume of 750 mL exerts a pressure of 98.0 kPa at 30 $\degree$ C.What pressure will the sample exert when it is compressed to 250 mL and cooled to -25 $\degree$ C?

A)353 kPa
B)241 kPa
C)359 kPa
D)39.9 kPa
E)26.7 kPa

Question 12

An oxygen tank kept at 20 $\degree$ C contains 28.0 moles of oxygen and the gauge reads 31.0 atm.After two weeks,the gauge reads 10.5 atm.How many moles of oxygen were used during the two-week period?

A)9.25 moles
B)7.5 moles
C)20.5 moles
D)18.5 moles
E)9.48 moles

Question 13

How many atoms of argon occupy 20.00 mL if the temperature is 200°C and the pressure is 2.00 × 10-3 Torr?

A)2.01 *10¹⁷
B)6.02* 10^-17
C)3.10 *10¹⁷
D)2.44 * 10¹⁹
E)2.80 *10 ^{- 11}

Question 14

The pressure at 20,000 feet above sea level is about 400.mmHg.This corresponds to

A)526 Pa
B)53.3 kg.m ^{- 1}.s ^{- 2}
C)0.526 Torr
D)0.526 kPa
E)53.3 kPa

Question 15

Calculate the pressure of 4.00 g of nitrogen gas in a 1.00-L container at 20.0 $\degree$ C.

A)0.469 atm
B)6.87 atm
C)96.2 atm
D)0.235 atm
E)3.44 atm

Question 16

The value of the gas law constant,R,in units of L.kPa.mol ^{- 1}.K ^{- 1} is

A)62.4
B)0.0821
C)0.0752
D)7.62
E)8.31

Question 17

The value of the gas law constant,R,in units of m³.Pa.mol ^{- 1}.0K ^{- 1} is

A)8.31
B)0.0821
C)7.62
D)0.0752
E)62.4

Question 18

What volume is occupied by 1,000.g of fluorine gas at 10.00°C at a pressure of 735 Torr?

A)22.3 L
B)44.6 L
C)621 L
D)632 L
E)4,690 L

Question 19

What volume is occupied by 1.00 kg of helium at 5.00 $\degree$ C at a pressure of 735 Torr?

A)5.97 * 10⁵ L
B)5.90 * 10³ L
C)2.95 * 10³ L
D)1.06 *10² L
E)5.60 *10³ L

Question 20

Calculate the mass of oxygen gas required to occupy a volume of 6.00 L at a pressure of 20.9 kPa and a temperature of 37.0 $\degree$ C.

A)1.56 g
B)0.408 g
C)0.779 g
D)13.1 g
E)0.0487 g

Question 21

Consider the following reaction: 4KO₂(s)+ 2CO₂(g) $\rightarrow$ 2K₂CO₃(s)+ 3O₂(g)
How many liters of oxygen are produced at STP if 10.5 moles of carbon dioxide are used at STP?

A)15.8
B)0.703
C)706
D)353
E)235

Question 22

A 0.479-g sample of nitrogen,oxygen or neon gas occupies a volume of 265 mL at 157 l Pa and 20.0 $\degree$ C.What are the molar mass and identity of the gas?

A)14.0 g.mol ^{- 1}, N
B)32.0 g.mol ^{- 1}, O₂
C)20.1 g.mol ^{- 1}, Ne
D)16.0 g.mol ^{- 1}, O
E)28.0 g.mol ^{- 1}, N₂

Question 23

The density of citronellal,a mosquito repellant,is 1.45 g.L ^{- 1} at 365 $\degree$ C and 50.0 kPa.What is the molar mass of citronellal?

A)73.2 g.mol ^{- 1}
B)154 g.mol ^{- 1}
C)95.7 g.mol ^{- 1}
D)37.5 g.mol ^{- 1}
E)88.0 g.mol ^{- 1}

Question 24

Calculate the number of moles of oxygen gas collected by displacement of water at 14.0 $\degree$ C if the atmospheric pressure is 790.Torr and the volume is 5.00 L.The vapor pressure of water at 14.0 $\degree$ C is 12.0 Torr.

A)0.0184
B)4.46
C)0.00335
D)0.217
E)0.224

Question 25

If 250.0 mL of a gas at STP weighs 2.00 g,what is the molar mass of the gas?

A)28.0 g.mol ^{- 1}
B)179 g.mol ^{- 1}
C)8.00 g.mol ^{- 1}
D)56.0 g.mol ^{- 1}
E)44.8 g.mol ^{- 1}

Question 26

What is the molar mass of a gas whose density is 3.55 g.L ^{- 1} at 110 $\degree$ C and a pressure of 736 Torr?

A)15.4 g.mol^-1
B)79.5 g.mol^-1
C)115 g.mol^-1
D)152 g.mol ^{- 1}
E)33.1 g.mol ^{- 1}

Question 27

Which gas is least dense at 1 atm and 25 $\degree$ C?

A)Hydrogen cyanide
B)Hydrogen sulfide
C)Carbon dioxide
D)Nitrogen
E)Ammonia

Question 28

Calculate the density of camphor,C₁₀H₁₆O,at 80 $\degree$ C and 12 Torr.

A)8.2 *10^-4 g.L^-1
B)0.083 g.L^-1
C)0.37 g.L^-1
D)0.62 g.L^-1
E)6.8 * 10^-3 g.L^-1

Question 29

Ammonium nitrate can decompose according to the following equation: NH₄NO₃(s) $\rightarrow$ N₂O(g)+ 2H₂O(g)
How many liters of gas are produced by decomposition of 160 g of ammonium nitrate at STP?

A)44.8
B)6.00
C)22.4
D)134
E)67.2

Question 30

What is the density of chlorine gas at 850 Torr and -12 $\degree$ C?

A)27.8 g.L ^{- 1}
B)3.70 g.L ^{- 1}
C)3.39 g.L ^{- 1}
D)7.40 g.L ^{- 1}
E)1.85 g.L ^{- 1}

Question 31

A sample of a gas weighing 15.1 g occupies 2.25 L at 1.75 atm and 20.0 $\degree$ C.If the empirical formula of the gas is NO₂,what is the molecular formula?

A)N₅O₁₀
B)N₃O₆
C)NO₂
D)N₄O₈
E)N₂O₄

Question 32

Which gas is most dense at 1 atm and 25 $\degree$ C?

A)Hydrogen cyanide
B)Hydrogen sulfide
C)Nitrogen monoxide
D)Carbon monoxide
E)Nitrogen dioxide

Question 33

At 80.0 $\degree$ C and 12.0 Torr,the density of camphor vapor is 0.0829 g.L^-1.What is the molar mass of camphor?

A)243 g.mol^-1
B)34.5 g.mol^-1
C)152 g.mol^-1
D)3490 g.mol ^{- 1}
E)20.3 g.mol ^{- 1}

Question 34

Ammonium nitrate can decompose according to the following equation: NH₄NO₃(s) $\rightarrow$ N₂O(g)+ 2H₂O(g)
How many liters of gas are produced by decomposition of 160 g of ammonium nitrate at -25 $\degree$ C and 86.0 kPa?

A)48.0
B)14.5
C)57.6
D)173
E)144

Question 35

Consider the following reaction: 4KO₂(s)+ 2CO₂(g) $\rightarrow$ 2K₂CO₃(s)+ 3O₂(g)
How many moles of KO₂ are needed to react with 75.0 L of carbon dioxide at -25 $\degree$ C and 215 kPa?

A)3.91
B)7.82
C)31.3
D)23.5
E)15.6

Question 36

What is the density of nitrogen gas at 740 Torr and -12 $\degree$ C?

A)0.637 g.L ^{- 1}
B)1.17 g.L ^{- 1}
C)1.27 g.L ^{- 1}
D)2.55 g.L ^{- 1}
E)9.56 g.L ^{- 1}

Question 37

Consider the following reaction: 4NaO₂(s)+ 2CO₂(g) $\rightarrow$ 2Na₂CO₃(s)+ 3O₂(g)
How many moles of NaO₂ are needed to react with 75.0 L of carbon dioxide at STP?

A)0.15
B)1.67
C)3.35
D)6.70
E)13.4

Question 38

A Group 17 or Group 18 gas has a density of 2.92 g.L ^{- 1} at 1.00 atm and 25 $\degree$ C.The gas is

A)helium
B)neon
C)fluorine
D)argon
E)chlorine

Question 39

The density of the vapor of allicin,a component of garlic,is 1.14 g.L ^{- 1} at 125 $\degree$ C and 175 Torr.What is the molar mass of allicin?

A)21.6 g.mol 1^{- 1}
B)50.8 g.mol ^{- 1}
C)273 g.mol ^{- 1}
D)869 g.mol ^{- 1}
E)162 g.mol ^{- 1}

Question 40

The empirical formula of a gas is CH₃O.If 2.77 g of the gas occupies 1.00 L at exactly 0 $\degree$ C at a pressure of 760 Torr,what is the molecular formula of the gas?

A)C₄H₁₂O₄
B)C₂H₆O₂
C)C₅H₁₅O₅
D)CH₃O
E)C₃H₉O₃

Question 41

Calcium cyanamide reacts with H₂O(g)at 150 $\degree$ C and 1.00 atm pressure: CaNCN(s)+ 3H₂O(g) $\rightarrow$ CaCO₃(s)+ 2NH₃(g)
If 80.0 L of NH₃(g)are produced,what volume of steam is required?

A)40.0 L
B)80.0 L
C)26.7 L
D)120. L
E)240. L

Question 42

The following experiment was carried out using a newly synthesized chlorofluorocarbon.Exactly 50 mL of the gas effused through a porous barrier in 157 s.The same volume of argon effused in 76 s under the same conditions.Which compound is the chlorofluorocarbon?

A)C₂Cl₄F₂
B)C₂ClF₅
C)C₂Cl₂F₄
D)C₂Cl₅F
E)C₂Cl₃F₃

Question 43

Sulfur dioxide reacts with oxygen gas to produce sulfur trioxide.How many moles of oxygen gas will react with 15.0 L of sulfur dioxide if both gases are at 101.3 kPa and 125 $\degree$ C?

A)0.230
B)0.115
C)0.731
D)0.919
E)0.459

Question 44

A sample of nitrogen gas collected at 24 $\degree$ C and 745 Torr has a vapor pressure of 745 Torr.

Question 45

Which of the following gases effuses slowest?

A)Fluorine
B)Carbon dioxide
C)Chlorine
D)Carbon monoxide
E)Nitrogen

Question 46

The following experiment was carried out using a newly synthesized chlorofluorocarbon.Exactly 50 mL of the gas effused through a porous barrier in 172 s.The same volume of argon effused in 76 s under the same conditions.Which compound is the chlorofluorocarbon?

A)C₂Cl₂F₄
B)C₂Cl₄F₂
C)C₂Cl₃F₃
D)C₂Cl₅F
E)C₂ClF₅

Question 47

If the average speed of a water molecule at 25 $\degree$ C is 640 m.s ^{- 1},what is the average speed at 100 $\degree$ C?

A)572 m.s ^{- 1}
B)5120 m.s ^{- 1}
C)801 m.s ^{- 1}
D)320 m.s ^{- 1}
E)1280 m.s ^{- 1}

Question 48

What mass of aluminum metal is required to produce 12.5 L of hydrogen gas at exactly 25 $\degree$ C and 1.00 atm? 2Al(s)+ 6H⁺(aq) $\rightarrow$ 2Al³⁺(aq)+ 3H₂(g)

A)20.7 g
B)22.6 g
C)10.0 g
D)13.8 g
E)9.19 g

Question 49

Calculate the mass of sulfur hexafluoride in a 2.00 L container at a pressure of 4.00 atm and a temperature of 78.0 $\degree$ C.The molar mass of sulfur hexafluoride is 146.1 g.mol ^{- 1}.

A)0.401 g
B)40.6 g
C)73.1 g
D)36.6 g
E)183 g

Question 50

Sulfur dioxide reacts with oxygen gas to produce sulfur trioxide.What volume of oxygen gas will react with 15.0 L of sulfur dioxide if both gases are at 101.3 kPa and 125 $\degree$ C?

A)30.0 L
B)15.0 L
C)7.50 L
D)5.00 L
E)3.75 L

Question 51

What is the root mean square speed of carbon dioxide molecules at 98 $\degree$ C?

A)153 m.s ^{- 1}
B)459 m.s ^{- 1}
C)45.6 m.s ^{- 1}
D)574 m.s ^{- 1}
E)236 m.s ^{- 1}

Question 52

The main composition of dry air at sea level is about 75.5% nitrogen,23.1% oxygen,and 1.3% argon.In a 1.00-g sample of dry air at 1.00 atm,calculate the partial pressure of argon gas.

Question 53

A mixture of oxygen and helium is 92.3% by mass oxygen.What is the partial pressure of oxygen if atmospheric pressure is 745 Torr?

A)412 Torr
B)446 Torr
C)688 Torr
D)333 Torr
E)299 Torr

Question 54

Oxygen can be produced in the laboratory by the reaction: 2KClO₃(s) $\rightarrow$ 2KCl(s)+ 3O₂(g)
How many moles of potassium chlorate are needed to produce 257 mL of oxygen,collected over water at 14 $\degree$ C and 97.6 kPa? The vapor pressure of water at 14 $\degree$ C is
1.60 kPa.

A)6.89 *10 ^{- 3}
B)7.00 *10 ^{- 3}
C)7.12 *10 ^{- 3}
D)2.06 *10 ^{- 3}
E)1.55*10 ^{- 3}

Question 55

What mass of aluminum metal is required to produce 4.48 L of hydrogen gas at exactly 0 $\degree$ C and 5.00 atm by reaction of the metal with excess strong acid?

A)1.80 g
B)9.00 g
C)36.0 g
D)18.0 g
E)180 g

Question 56

If it takes 15 s for a certain sample of neon to effuse through a porous barrier,it will take ________________________________ (15 s,greater than 15 s,less than 15 s)for the same amount of nitrogen gas to effuse through the barrier under the same conditions.

Question 57

If the average speed of a carbon dioxide molecule is 410 m.s ^{- 1} at 25 $\degree$ C,what is the average speed of a molecule of methane at the same temperature?

A)680 m.s ^{- 1}
B)410 m.s ^{- 1}
C)1130 m.s ^{- 1}
D)1000 m.s ^{- 1}
E)247 m.s ^{- 1}

Question 58

Oxygen can be produced in the laboratory by the following reaction: 2KClO₃(s) $\rightarrow$ 2KCl(s)+ 3O₂(g)
How many moles of potassium chlorate are needed to produce 2.75 L of oxygen,collected over water at 37 $\degree$ C and 94.9 kPa? The vapor pressure of water at 37 $\degree$ C is
6.28 kPa.

A)0.142
B)6.75 *10 ^{- 2}
C)7.20 *10 ^{- 2}
D)6.30 *10 ^{- 2}
E)0.189

Question 59

Which of the following gases will have the largest root mean square speed at 100 $\degree$ C?

A)water
B)argon
C)methane
D)nitrogen
E)oxygen

Question 60

Lithium metal reacts with nitrogen gas to produce lithium nitride.What volume of nitrogen gas at 2.00 atm and 175 $\degree$ C is required to produce 75.0 g of lithium nitride?

A)30.9 L
B)119 L
C)79.2 L
D)39.6 L
E)15.5 L

Question 61

How many liters of hydrogen gas measured at 25.0 $\degree$ C and 745 Torr are produced by detonation of 59.0 g of TNT,trinitrotoluene,C₇H₅(NO₂)₃?

A)0.544 L
B)6.94 L
C)1.36 L
D)16.2 L

Question 62

Consider two cylinders of gas,both with a volume of 25 L and at 1 atm and 25 $\degree$ C.If one cylinder contains nitrogen gas and the other argon,which of the following statements are true and which are false.
(a)The temperature of the gases is different.
(b)The average molecular speed of the gases is the same.
(c)The average kinetic energy of the gases is the same.

Question 63

Consider two flasks at 25 $\degree$ C,one contains an ideal gas and the other contains the real gas SO₃.Which statement regarding these gases is true?

A)After the temperature is increased about 100 K, the pressure of the ideal gas will be smaller than the pressure of SO₃ because the van der Waals coefficient a for SO₃ is large.
B)As the temperature is decreased, the ideal gas will liquefy first because ideal gases have larger values of the van der Waals coefficient b.
C)After the temperature has been lowered about 100 K, the pressure of the ideal gas will be smaller than the pressure of SO₃ because the van der Waals coefficient a for SO₃ is large.
D)As the temperature approaches 0 K, the volume of the ideal gas will be larger than the volume of SO₃ because ideal gases lack intermolecular forces.
E)As the temperature approaches 0 K, the volume of the ideal gas will be smaller than the volume of SO₃ because ideal gases have larger values of the van der Waals coefficient a.

Question 64

A plot of the Maxwell distribution against speed for different molecules shows that

A)heavy molecules have a higher average speed.
B)light molecules have a very narrow range of speeds.
C)heavy molecules have a wide range of speeds.
D)light molecules have a lower average speed.
E)heavy molecules travel with speeds close to their average values.

Question 65

Ideal gases and real gases behave most similarly under which of the following conditions?

A)Low temperatures and low pressures.
B)Low temperatures and high pressures.
C)High pressures and low molar masses.
D)High temperatures and high pressures.
E)High temperatures and low pressures.

Question 66

Helium,H₂,and neon all have very small values of the van der Waals coefficient "a",whereas Cl₂,xenon,and water have large values.Which gases would you expect to be able to be liquefied by expansion?

Question 67

Consider the following van der Waals coefficients: Which of the following gases has the smallest attractive forces?

A)Ammonia
B)Hydrogen
C)Neon
D)Helium
E)Chlorine

Question 68

A 1.00-L sample of C₂H₄(g)at 2.00 atm and 293 K is burned in 8.00 L of oxygen gas at the same temperature and pressure to form carbon dioxide and water.If the reaction goes to completion,what is the final volume of all gases at 2.00 atm and 293 K?

A)5.33 L
B)9.00 L
C)8.00 L
D)3.00 L
E)5.00 L

Question 69

A 6.00-L sample of C₂H₄(g)at 2.00 atm and 293 K is burned in 6.00 L of oxygen gas at the same temperature and pressure to form carbon dioxide and water.If the reaction goes to completion,what is the final volume of all gases at 2.00 atm and 293 K?

A)2.66 L
B)6.00 L
C)2.00 L
D)1.33 L
E)4.00 L

Question 70

Consider the following statements:1.Real gases act more like ideal gases as the temperature increases.2.When n and T are constant,a decrease in P results in a decrease in V.3.At 1 atm and 273 K,every molecule in a sample of a gas has the same speed.4.At constant T,CO₂ molecules at 1 atm and H₂ molecules at 5 atm have the same average kinetic energy.
Which of these statements is true?

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

Question 71

How many liters of nitrogen gas measured at 25.0 $\degree$ C and 745 Torr are produced by detonation of 90.8 g of TNT,trinitrotoluene,C₇H₅(NO₂)₃?

A)0.839 L
B)1.26 L
C)9.98 L
D)15.0 L

Question 72

Which molecules of the following gases will have the greatest average kinetic energy?

A)CO₂ at 1 atm and 298 K
B)N₂ at 1 atm and 298 K
C)All the molecules have the same kinetic energy.
D)He at 0.1 atm and 298 K
E)H₂ at 0.5 atm and 298 K

Question 73

Which molecules of the following gases will have the greatest root mean square speed?

A)Nitrogen at 1 atm and 273 K
B)All the molecules have the same root mean square speed.
C)Hydrogen at 0.5 atm and 273 K
D)Argon at 1 atm and 273 K
E)Helium at 0.1 atm and 273 K

Question 74

Which of the following gases would you predict to have the largest value of the van der Waals coefficient b?

A)C₂F₂Cl₂
B)C₂FCl₅
C)C₂F₄
D)Cl₂
E)F₂

Question 75

Which of the following gases would not be expected to cool as it expands?

A)NH₃
B)Cl₂
C)Xe
D)H₂O
E)He

Question 76

Consider the following van der Waals coefficients: Which of the following gases has the largest attractive forces?

A)Neon
B)Ammonia
C)Chlorine
D)Water
E)Helium

Question 77

What is the molar volume of a nitrogen gas at -27.0^oC and 1 atm?

A)2.22 L
B)22.4 L
C)24.6 L
D)20.2 L

Question 78

How many liters of carbon dioxide measured at 25.0 $\degree$ C and 821 Torr would be produced by the combustion of 319 g of glucose,C₆H₁₂O₆?

A)3.37 L
B)40.1 L
C)241 L
D)20.2 L

Question 79

What is the vapor pressure of geraniol,molar mass 155 g/mol,if the density of the vapor at 260 $\degree$ C is 0.480 g/L?

A)50.2 Torr
B)103 Torr
C)0.0661 Torr
D)0.103 Torr

Question 80

A plot of the Maxwell distribution for the same gas against temperature shows that

A)at high temperatures, most molecules have speeds close to their average speed.
B)as the temperature increases, a high proportion of molecules have very slow speeds.
C)as the temperature decreases, the spread of speeds widens.
D)as the temperature decreases, a high proportion of molecules have very high speeds.
E)at low temperatures, most molecules have speeds close to their average speed.