Deck 9: Gases: Their Properties and Behavior

Question 1

An approximation of absolute zero was made from an extrapolation of

A)P vs.1/V
B)V vs.T
C)n vs.V
D)V vs.1/T

Answer 1

V vs.T

Question 2

The pressure in the eye of a hurricane is less than atmospheric pressure.Which one of the following pressure readings could not have been taken in the eye of a hurricane?

A)15 lbs/in²
B)69 cm Hg
C)690 mm Hg
D)9)22 × 10⁴ Pa

Answer 2

15 lbs/in²

Question 3

What is the pressure in a gas container that is connected to an open-end U-tube manometer if the pressure of the atmosphere is 752 torr and the level of mercury in the arm connected to the container is 8.60 cm higher than the level of mercury open to the atmosphere?

A)666 mm Hg
B)743 mm Hg
C)761 mm Hg
D)838 mm Hg

Answer 3

666 mm Hg

Question 4

Which of the following instruments directly measures the pressure of a gas?

A)spectrometer
B)manometer
C)polarimeter
D)gas chromatograph

Question 5

Which of the following equations represents "Boyle's law"?

A) = k
B) = k
C)PV = k
D)V = nk

Question 6

If mercury (density = 13.6 g/cm³)at a height of 745 mm Hg in a mercury barometer is replaced with water (density = 1.00 g/cm³),under the same conditions the height of water will be

A)0)180 ft
B)2)44 ft
C)33.2 ft
D)399 ft

Question 7

If the pressure in a gas container that is connected to an open-end U-tube manometer is 106 kPa and the pressure of the atmosphere at the open end of the tube is 742 mm Hg,the level of mercury in the tube will be

A)53 mm higher in the arm open to the atmosphere.
B)53 mm higher in the arm connected to the gas cylinder.
C)636 mm higher in the arm open to the atmosphere.
D)636 mm higher in the arm connected to the gas cylinder.

Question 8

Automobile tires are typically inflated to about 30 pounds of pressure per square inch.What is the typical air pressure of a tire in kPa?

A)2)0 × 10^-3 kPa
B)2)0 kPa
C)2)1 × 10² kPa
D)2)1 × 10⁵ kPa

Question 9

Which is the smallest quantity of pressure?

A)1 atm
B)1 centimeter of Hg
C)1 mm Hg
D)1 pascal

Question 10

When temperature-volume measurements are made on 1.0 mol of gas at 1.0 atm,a plot V versus T results in a

A)hyperbola.
B)parabola.
C)sine curve.
D)straight line.

Question 11

In an open end manometer,one end of a U-tube filled with mercury is attached to a gas-filled container and the other end is open to the atmosphere.If the gas pressure in the container is less than atmospheric pressure

A)Hg will be forced out of the open end of the U-tube.
B)the difference between the Hg levels in the two arms will be greater than 76 cm.
C)the Hg level will be higher in the arm connected to the container.
D)the Hg level will be higher in the arm open to the atmosphere.

Question 12

The SI unit for pressure is the

A)atmosphere.
B)MM Hg.
C)newton.
D)pascal.

Question 13

When pressure-volume measurements are made on 1.0 mol of gas at constant temperature,a plot V versus P results in a

A)hyperbola.
B)parabola.
C)sine curve.
D)straight line.

Question 14

Suppose you needed to closely monitor small changes in pressure inside a container using an open end manometer.For the best accuracy,the substance in the manometer should

A)be a solid.
B)be mercury.
C)have a high density.
D)have a low density.

Question 15

Carbon dioxide is a gas which causes environmental concern because of the greenhouse effect.What is the approximate percentage (by volume)of CO₂ in the atmosphere?

A)less than 0.1%
B)about 1%
C)about 10%
D)more than 20%

Question 16

A container filled with gas is connected to an open-end U-tube manometer that is filled with mineral oil.The pressure in the gas container is 773 mm Hg and atmospheric pressure is 754 mm Hg.What will be the difference in the levels of mineral oil in the two arms of the manometer if the densities of Hg and mineral oil are 13.6 g/mL and 0.822 g/mL respectively?

A)1)15 mm
B)15.6 mm
C)19.0 mm
D)314 mm

Question 17

Which law does the equation,
= k represent?

A)Avogadro's law
B)Boyle's law
C)Charles' law
D)Graham's law

Question 18

Pressure is defined as

A)force divided by unit area.
B)force times unit area.
C)mass divided by acceleration.
D)mass times acceleration.

Question 19

Which of the following is not equivalent to 1 atm pressure?

A)10 cm Hg
B)14.7 lb/in²
C)101 kPa
D)760 mm Hg

Question 20

Which one of the following is not used to describe the condition of a gas?

A)number of moles
B)polarity
C)temperature
D)volume

Question 21

What is the Celsius temperature of 100.0 g of chlorine gas in a 40.0-L container at 800 mm Hg?

A)-91°C
B)91°C
C)182°C
D)364°C

Question 22

A basketball is inflated to a pressure of 1.50 atm in a 20.0°C garage.What is the pressure of the basketball outside where the temperature is -5.00°C?

A)1)37 atm
B)1)42 atm
C)1)58 atm
D)1)64 atm

Question 23

Cyanogen is a gas which contains 46.2% C and 53.8% N by mass.At a temperature of 25°C and a pressure of 750 mm Hg,1.50 g of cyanogen occupies 0.714 L.What is the molecular formula of cyanogen?

A)CN
B)C₂N₂
C)C₃N₄
D)C₄N₅

Question 24

The volume of 350.mL of gas at 25°C is decreased to 125 mL at constant pressure.What is the final temperature of the gas?

A)-167°C
B)8)9°C
C)70°C
D)561°C

Question 25

A gas occupies 22.4 L at STP and 14.5 L at 100°C and 2.00 atm pressure.How many moles of gas did the system gain or lose?

A)0)06 moles gained
B)0)03 moles gained
C)0)03 moles lost
D)0)05 moles lost

Question 26

A 1.75 L container filled with CO₂ gas at 25°C and 225 kPa pressure springs a leak.When the container is re-sealed,the pressure is 185 kPA and the temperature is 10°C.How many moles of gas were lost?

A)0)0213 mol
B)0)463 mol
C)0)561 mol
D)2)16 mol

Question 27

A balloon filled with helium gas at 20°C occupies 2.91 L at 1.00 atm.The balloon is immersed in liquid nitrogen at -196°C,raising the pressure to 5.20 atm.What is the volume of the balloon in the liquid nitrogen?

A)0)15 L
B)2)1 L
C)4)0 L
D)58 L

Question 28

If the number of moles of gas is doubled at constant temperature and volume,the pressure of the gas

A)is halved.
B)is doubled.
C)is quadrupled.
D)remains the same.

Question 29

A 1.00 L flask contains nitrogen gas at 25°C and 1.00 atm pressure.What is the final pressure in the flask if an additional 2.00 g of N₂ gas is added to the flask and the flask cooled to -55°C?

A)1)28 atm
B)2)01 atm
C)2)56 atm
D)3)29 atm

Question 30

A steel bottle contains argon gas at STP.What is the final pressure if the temperature is changed to 115°C?

A)0)704 atm
B)0)768 atm
C)1)30 atm
D)1)42 atm

Question 31

How many grams of O₂ gas are there in a 5.00-L cylinder at 4.00 × 10³ mm Hg and 23°C?

A)17.3 g
B)34.7 g
C)446 g
D)2)63 × 10⁴ g

Question 32

How many molecules of N₂ are in a 500.0 mL container at 780 mm Hg and 135°C?

A)8)76 × 10²¹
B)9)23 × 10²¹
C)2)65 × 10²²
D)2)79 × 10²²

Question 33

A 75.0 L steel tank at 20.0°C contains acetylene gas,C₂H₂,at a pressure of 1.39 atm.Assuming ideal behavior,how many grams of acetylene are in the tank?

A)4)33 g
B)6)01 g
C)113 g
D)1650 g

Question 34

Three identical flasks contain three different gases at standard temperature and pressure.Flask A contains CH₄,flask B contains CO₂,flask C contains N₂.Which flask contains the largest number of molecules?

A)flask A
B)flask B
C)flask C
D)All flasks contain the same number of molecules.

Question 35

"Equal volumes of different gases at the same temperature and pressure contain the same molar amounts" is another way of stating

A)Avogadro's law.
B)Boyle's law.
C)Charles' law.
D)Graham's law.

Question 36

What is the value of the gas constant,R,in units of
?

A)1)080 × 10^-4
B)0)1080
C)62.36
D)6)236 × 10⁴

Question 37

An "empty" aerosol can at 25°C still contains gas at 1.00 atmosphere pressure.If an "empty" can is thrown into a 475°C fire,what is the final pressure in the heated can?

A)5)26 × 10^-2 atm
B)0)398 atm
C)2)51 atm
D)19.0 atm

Question 38

A 0.286-g sample of gas occupies 125 mL at 60.cm of Hg and 25°C.What is the molar mass of the gas?

A)5)9 g/mol
B)44 g/mol
C)59 g/mol
D)71 g/mol

Question 39

A gas bottle contains 0.650 mol of gas at 730 mm Hg pressure.If the final pressure is 1.15 atm,how many moles of gas were added to the bottle?

A)0)0680 mol
B)0)128 mol
C)0)717 mol
D)0)778 mol

Question 40

What is the volume of 10.0 g of argon gas at 157°C and 2.50 kPa pressure?

A)1)29 L
B)3)53 L
C)131 L
D)358 L

Question 41

How many liters of SO₃(g)are produced at 25°C and 1.00 atm from the combustion of 1.00 kg of coal which is 1.00% S by weight? Assume all the sulfur in the coal ends up as SO₃.

A)0)640 L
B)5)08 L
C)7)63 L
D)11.4 L

Question 42

The action of some commercial drain cleaners is based on the following reaction:
2 NaOH(s)+ 2 Al(s)+ 6 H₂O(l)→ 2 NaAl(OH)₄(s)+ 3 H₂(g)
What is the volume of H₂ gas formed at STP when 4.32 g of Al reacts with excess NaOH?

A)2)39 L
B)3)59 L
C)5)38 L
D)5)87 L

Question 43

Chloroform is a volatile liquid once commonly used in the laboratory but now being phased out due to its ozone depletion potential.If the pressure of gaseous chloroform in a flask is 195 mm Hg at 25°C and its density is 1.25 g/L,what is the molar mass of chloroform?

A)10.0 g/mol
B)76.3 g/mol
C)119 g/mol
D)None of these

Question 44

Hydrogen gas is collected over water in an inverted buret.If the atmospheric pressure is 745 mm Hg,the vapor pressure of water is 18 mm Hg,and a 15.0 cm-high column of water remains in the buret,the pressure of the hydrogen gas is

A)763 mm.
B)745 mm Hg.
C)727 mm Hg.
D)less than 727 mm Hg.

Question 45

What is the density of fluorine gas at STP?

A)0)590 g/L
B)0)848 g/L
C)1)55 g/L
D)1)70 g/L

Question 46

How many liters of oxygen are needed to exactly react with 27.8 g of methane at STP?
CH₄(g)+ 2 O₂(g)→ CO₂(g)+ 2 H₂O(l)

A)19.5 L
B)39.0 L
C)77.6 L
D)85.0 L

Question 47

Given three cylinders containing O₂ gas at the same volume and pressure.Cylinder A is at -20°C,cylinder B is at -15°F,cylinder C is at 260 K.Which cylinder contains the largest mass of oxygen?

A)cylinder A
B)cylinder B
C)cylinder C
D)All cylinders contain the same mass of O₂.

Question 48

At STP how many liters of NH₃ can be produced from the reaction of 6.00 mol of N₂ with 6.00 mol of H₂?
N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

A)44.8 L
B)89.6 L
C)134 L
D)269 L

Question 49

In the laboratory,hydrogen gas is usually made by the following reaction:
Zn(s)+ 2 HCl(aq)→ H₂(g)+ ZnCl₂(aq)
How many liters of H₂ gas,collected over water at an atmospheric pressure of 752 mm Hg and a temperature of 21.0°C,can be made from 1.566 g of Zn and excess HCl? The partial pressure of water vapor is 18.65 mm Hg at 21.0°C.

A)0)0428 L
B)0)573 L
C)0)585 L
D)0)599 L

Question 50

Which of the following would have a density of 1.21 g/L at 7.0°C and 0.987 atm?

A)Ar
B)N₂
C)Ne
D)O₂

Question 51

A lungful of air (500 mL)contains 4.1% CO₂ by volume.How many grams of KO₂(s)is needed to remove the CO₂ from a lungful of air at STP according to the following reaction?
4 KO₂(s)+ 2 CO₂(g)→ 2 K₂CO₃(s)+ 3 O₂(g)

A)0)065 g
B)0)13 g
C)0)26 g
D)1)2 g

Question 52

A balloon contains 0.76 mol N₂,0.18 mol O₂,0.031 mol He,and 0.026 mol H₂ at 739 mm Hg.What is the partial pressure of O₂?

A)19 mm Hg
B)23 mm Hg
C)130 mm Hg
D)560 mm Hg

Question 53

A 10.0-L flask containing He,2.00 mole of Ar,and 3.00 mole of Ne has a total pressure of 24.5 atm at 25°C.How many moles of He are in the flask?

A)5)00 mol
B)10.0 mol
C)114 mol
D)119 mol

Question 54

One mole of which gas has the greatest density at STP?

A)Ar
B)N₂
C)CO
D)All three gases have the same density.

Question 55

When 15.0 g of zinc metal reacts with excess HCl,how many liters of H₂ gas are produced at STP?

A)0)229 L
B)0)458 L
C)5)14 L
D)10.3 L

Question 56

If the Earth's ozone (O₃)layer has a total volume of 1.00 × 10²⁰ km³,a partial pressure of 1.6 × 10^-9 atm,and an average temperature of 230 K,how many ozone molecules are in the Earth's ozone layer?

A)2)3 × 10³⁵ molecules
B)5)1 × 10³⁵ molecules
C)2)3 × 10⁴⁵ molecules
D)5)1 × 10⁴⁵ molecules

Question 57

A 1.000 kg sample of nitroglycerine,C₃H₅N₃O₉,explodes and releases gases with a temperature of 1985°C at 1.000 atm.What is the volume of gas produced?
4 C₃H₅N₃O₉(l)→ 12 CO₂(g)+ 10 H₂O(g)+ 6 N₂(g)+ O₂(g)

A)816.4 L
B)3878 L
C)5203 L
D)5919 L

Question 58

At STP how many grams of Mg are required to produce 35 mL of H₂ in the reaction shown below?
Mg(s)+ 2 HCl(aq)→ H₂(g)+ MgCl₂(aq)

A)0)035 g
B)0)038 g
C)26 g
D)29 g

Question 59

What is the total pressure in a 10.0 L flask which contains 0.127 mol of H₂(g)and 0.288 mol of N₂(g)at 20.0°C?

A)0)306 atm
B)0)681 atm
C)0)693 atm
D)0)998 atm

Question 60

How many grams of XeF₆ are required to react with 0.579 L of hydrogen gas at 2.46 atm and 45°C in the reaction shown below?
XeF₆(s)+ 3 H₂(g)→ Xe(g)+ 6 HF(g)

A)3)65 g
B)4)46 g
C)13.4 g
D)40.2 g

Question 61

Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K.Cylinder A contains Ar,cylinder B contains Cl₂,and cylinder C contains N₂.According to the kinetic molecular theory,which gas has the highest density?

A)Ar
B)Cl₂
C)N₂
D)All have identical densities

Question 62

The ozone molecules in the stratosphere absorb much of the ultraviolet radiation from the sun,protecting life on Earth.At a certain altitude,the temperature of the stratosphere is 240 K and the partial pressure of ozone is 1.4 × 10^-7 atm.Calculate the number of ozone molecules present in 1.00 L of atmosphere at that altitude.

A)2)1 × 10¹⁵ molecules of O₃
B)4)3 × 10¹⁵ molecules of O₃
C)8)0 × 10³¹ molecules of O₃
D)1)8 × 10³² molecules of O₃

Question 63

According to the kinetic molecular theory,the pressure of a gas in a container will decrease if the

A)number of collisions with the container wall increases.
B)number of moles of the gas increases.
C)temperature of the gas decreases.
D)volume of the container decreases.

Question 64

The mixing of different gases by random molecular motion with frequent collisions is called

A)Avogadro's law.
B)compressibility.
C)diffusion.
D)effusion.

Question 65

A 0.500 g sample containing Ag₂O and inert material is heated,causing the silver oxide to decompose according to the following equation:
2 Ag₂O(s)→ 4 Ag(s)+ O₂(g)
If 13.8 mL of gas are collected over water at 27°C and 1.00 atm external pressure,what is the percentage of silver oxide in the sample? The partial pressure of water is 26.7 mm Hg at 27°C.

A)12.5%
B)25.1%
C)50.1%
D)51.9%

Question 66

What is the average speed (actually the root-mean-square speed)of a neon atom at 27°C?

A)5)78 m/s
B)19.3 m/s
C)183 m/s
D)609 m/s

Question 67

Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K.Cylinder A contains Ar,cylinder B contains Cl₂,and cylinder C contains N₂.According to the kinetic molecular theory,which gas has the highest average speed?

A)Ar
B)Cl₂
C)N₂
D)All have identical average speeds

Question 68

What is the temperature of CO₂ gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

A)1)32 K
B)9)92 × 10² K
C)1)31 × 10³ K
D)9)92 × 10⁵ K

Question 69

Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K.Cylinder A contains Ar,cylinder B contains Cl₂,and cylinder C contains N₂.According to the kinetic molecular theory,which gas has the highest pressure?

A)Ar
B)Cl₂
C)N₂
D)All have identical pressures

Question 70

Some assumptions from the kinetic molecular theory are listed below.Which one is most frequently cited to explain diffusion of a gas?

A)The average kinetic energy of gas particles is proportional to the Kelvin temperature.
B)Collisions of gas particles are elastic and total kinetic energy of the gas is constant.
C)A gas consist of tiny particles moving in random straight line motion.
D)The volume of the particles is negligible compared to the volume of the gas.

Question 71

Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K.Cylinder A contains Ar,cylinder B contains Cl₂,and cylinder C contains N₂.According to the kinetic molecular theory,which gas has the highest collision frequency?

A)Ar
B)Cl₂
C)N₂
D)All have identical collision frequencies

Question 72

At what temperature will sulfur hexafluoride molecules have the same average speed as argon atoms at 20°C?

A)-22.0°C
B)73.2°C
C)381°C
D)799°C

Question 73

Each of three identical 15.0-L gas cylinders contains 7.50 mol of gas at 295 K.Cylinder A contains Ar,cylinder B contains Cl₂,and cylinder C contains N₂.According to the kinetic molecular theory,which gas has the highest average kinetic energy?

A)Ar
B)Cl₂
C)N₂
D)All have identical average kinetic energies

Question 74

You are given two flasks of equal volume.One contains H₂ at 0°C and 1 atm while the other contains CO₂ at 0°C and 2 atm.Which of the following quantities will be the same for both flasks?

A)average molecular kinetic energy
B)average molecular speed
C)density
D)number of molecules present

Question 75

Some assumptions from the kinetic molecular theory are listed below.Which one is most frequently cited to explain Charles' law?

A)The average kinetic energy of gas particles is proportional to the Kelvin temperature.
B)Collisions of gas particles are elastic and total kinetic energy of the gas is constant.
C)A gas consists of tiny particles moving in random straight line motion.
D)The volume of the particles is negligible compared to the volume of the gas.

Question 76

A process by which gas molecules escape through a tiny hole in a membrane into a vacuum without collisions is called

A)Boyle's law.
B)diffusion.
C)effusion.
D)sublimation.

Question 77

Which one of the following gases will have the highest rate of effusion?

A)NO₂
B)N₂O
C)N₂O₄
D)NO₃

Question 78

Some assumptions from the kinetic molecular theory are listed below.Which one is most frequently cited to explain compressibility of a gas?

A)The average kinetic energy of gas particles is proportional to the Kelvin temperature.
B)Collisions of gas particles are elastic and total kinetic energy of the gas is constant.
C)A gas consist of tiny particles moving in random straight line motion.
D)The volume of the particles is negligible compared to the volume of the gas.

Question 79

Which of the following gases has the lowest average speed at 25°C?

A)CH₄
B)H₂S
C)NH₃
D)O₂

Question 80

Which of the following gases has the highest average speed at 400K?

A)CO₂
B)N₂O₄
C)SF₆
D)UF₆