Deck 6: Properties of Gases: The Air We Breathe

Question 1

The atmospheric pressure in the eye of a hurricane is found to be 26.6 in of mercury. The pressure in the eye of this hurricane is ________

A)760 mm Hg.
B)1.00 Pa.
C)0.889 atm.
D)0.987 bar.
E)0.785 atm.

Answer 1

0.889 atm.

Question 2

A gas, initially at 2.50 atm and 3.00 L, expands to a volume of 10.00 L. What is the new pressure of the gas?

A)0.75 atm
B)1.33 atm
C)2.10 atm
D)8.33 atm
E)12.0 atm

Answer 2

0.75 atm

Question 3

A barometer measures a pressure of 745 mm Hg. What is this pressure in atm?

A)0.980 atm
B)1.02 atm
C)1.03 atm
D)1.00 atm
E)0.556 atm

Answer 3

0.980 atm

Question 4

A can of Diet Coke in a refrigerator has a pressure of 52 mmHg. What is the pressure in millibar? Recall 1.013 bar = 1 atm.

A)6.9 mbar
B)4.0 mbar
C)57 mbar
D)40 mbar
E)69 mbar

Question 5

The SI unit of force is the Newton (N), and the unit of pressure is the Pascal (Pa). In SI base units, 1 N = 1 kg m s^-2, and 1 Pa ________

A)1 kg m^-1 s^-2.
B)1 kg m²s^-2.
C)1 kg m^-1 s^-1.
D)1 kg m^-2 s^-2.
E)1 kg s^-2.

Question 6

What height of water (in meters) is necessary to measure a pressure of 760 mm Hg? The density of mercury is 13.79 g/cm³, and the density of water is 1.00 g/cm³.

A)0.760 m
B)1.05 10⁴ m
C)0.105 m
D)10.5 m
E)55.1 mm

Question 7

Which statement about the properties of a gas is not correct?

A)Unlike a solid or a liquid, gases expand to occupy the entire volume of their container.
B)When the temperature is changed, the volume of gas changes much more than the volume of a solid or liquid.
C)Different gases are completely miscible with each other.
D)The density of a gas typically is much larger than the density of a solid or liquid.
E)When the pressure is changed, the volume of a gas changes much more than the volume of a solid or liquid.

Question 8

Gases can typically be mixed in any proportion, unless they chemically react. This property is called ________

A)density.
B)miscibility.
C)diffusion.
D)immiscibility.
E)effusion.

Question 9

If the pressure of a gas triples, by what factor does the volume change, assuming constant temperature?

A)1/3
B)3
C)1
D)9
E)1/9

Question 10

What is the pressure in the gas bulb connected to the mercury manometer shown in the diagram if the ambient pressure is 750 torr? The heights labeled in the diagram are 15 mm and 21 mm.

A)756 torr
B)771 torr
C)729 torr
D)765 torr
E)735 torr

Question 11

The composition of Earth's atmosphere by volume is ________ nitrogen, ________ oxygen, 0.93% argon, 0.039% carbon dioxide, around 1% water vapor, and small amounts of other gases.

A)78%; 21%
B)68%; 31%
C)88%; 11%
D)49%; 49%
E)22%; 77%

Question 12

What pressure will be measured (in Pa) if a gas is exerting a force of 10.00 N on a mercury barometer with an inner diameter of 10.00 mm?
Recall that the area of a circle is and that 1 N = 1 kg m/s².

A)3.183 Pa
B)1.273 Pa
C)3.183 Pa
D)1.273 Pa

Question 13

Which of the following substances will require the highest column for measuring an atmospheric pressure of 0.950 atm? (Assume all the barometers have columns with the same diameter.)

A)Mercury (d = 13.59 g/cm³)
B)Ethanol (d = 0.79 g/cm³)
C)Ethylene glycol (d = 1.09 g/cm³)
D)Water (d = 1.00 g/cm³)
E)Carbon tetrachloride (d = 1.58 g/cm³)

Question 14

A soft drink rises in a straw when you suck on the straw because ________

A)the vacuum pulls the liquid up the straw.
B)capillary forces attract the liquid to the walls of the straw.
C)the air pressure inside the straw is less than the air pressure outside the straw.
D)the air pressure inside the straw is greater than the air pressure outside the straw.
E)the liquid level inside the straw is pushed up by the liquid level outside the straw.

Question 15

The cold inflation pressure of many car tires is 30 lb/in², which is the gauge pressure. If 1 atm = 14.7 lb/in², what is the gauge pressure of a car tire in torr?

A)2.04 torr
B)1.55 torr
C)441 torr
D)0.580 torr
E)1.12 torr

Question 16

The pressure of a gas is inversely proportional to ________

A)the volume of the gas.
B)the number of gas particles.
C)the temperature of the gas.
D)the molar mass of the gas.
E)the mass of the gas.

Question 17

Two identical cement blocks are placed on a glass table in different positions, as shown in the diagram. Which statement about these blocks is correct?

A)A exerts more pressure on the table.
B)B exerts more pressure on the table.
C)Both blocks exert the same pressure on the table.
D)A exerts more force on the table.
E)B exerts more force on the table.

Question 18

A 1.25 L bottle of soda exerts a force of ________ N and a pressure of ________ Pa when placed on a table. The round cylindrical bottle has a diameter of 10.0 cm and a height of 25.0 cm. Assume that the density of the soda is 1.0 g/mL, and that the mass of the plastic bottle is negligible. Remember, the acceleration due to gravity is 9.81 m/s²; 1 Newton = 1 kg m/s², 1 Pascal = 1 kg/(m s²), , and .

A)9.8 N; 1,200 Pa
B)12 N; 390 Pa
C)12 N; 16 Pa
D)12 N; 12 Pa
E)12 N; 1,600 Pa

Question 19

What pressure (in Pa) will be exerted on the bottom of a 63.5 kg hiker's foot when she stands on a rusty nail? Assume the diameter of the tip of the nail is 1.00 mm. The acceleration due to gravity is 9.81 m/s². Recall that the area of a circle is: A = $\pi$ r² and that 1 Pa = 1 kg m^-1 s^-2.

A)1.98 Pa
B)7.93 Pa
C)1.98 Pa
D)7.93 Pa
E)7.93 Pa

Question 20

A balloon is filled with 3.00 L of helium at a pressure of 765 torr. What is the volume of the balloon at an altitude where the pressure in the balloon is 530 torr?

A)0.231 L
B)4.33 L
C)2.08 L
D)1.00 L
E)3.00 L

Question 21

Which of the gases shown here will exert the lowest pressure, assuming that each container has the same volume and temperature?

A)
B)
C)
D)

Question 22

The temperature of a gas is directly proportional to ________

A)the number of moles of the gas.
B)the identity of the gas.
C)the volume of the gas.
D)the density of the gas.
E)the mass of the gas.

Question 23

Which of the following graphs shows the correct relationship between the temperature and volume of an ideal gas at a given pressure? Note the origin corresponds to V = 0 and T = 0.

A)
B)
C)
D)

Question 24

A sample of gas at 4.0 atm and 25.0 mL is heated from 25 ^$\circ$ C to 40 ^$\circ$ C. If the pressure remains constant, what is the final volume of the gas?

A)26.2 mL
B)40.0 mL
C)23.8 mL
D)105 mL
E)25.0 mL

Question 25

Four containers, each with the same volume and at the same temperature, are shown in the following diagrams. Which container is at the highest pressure?

A)
B)
C)
D)

Question 26

A 1.50 mol sample of He occupies a volume of 2.50 L at a pressure of 14.7 atm. What will be the pressure of a 1.50 mol sample of H₂ gas under the same conditions?

A)7.33 atm
B)14.7 atm
C)29.4 atm
D)1.00 atm
E)24.5 atm

Question 27

Which statement A-D regarding an ideal gas is not correct?

A)The volume occupied by an individual molecule is negligible.
B)No interactions occur between molecules other than hard sphere collisions.
C)Molecules move in random directions and collide with each other.
D)The volume occupied by 1 mol of molecules at STP is 22.4 L.
E)Statements A-D all are correct.

Question 28

The volume of a 15.0 g sample of N₂ gas at a pressure of 2.7 atm is 6.24 L. What is the temperature of the sample?

A)14 ^$\circ$ C
B)190 ^$\circ$ C
C)3.8 ^$\circ$ C
D)110 ^$\circ$ C
E)76 ^$\circ$ C

Question 29

A sample of gas at 30 ^$\circ$ C changes volume from 20.0 mL to 25.0 mL. If the pressure remained constant, what is the final temperature of the gas?

A)31 ^$\circ$ C
B)-31 ^$\circ$ C
C)24 ^$\circ$ C
D)106 ^$\circ$ C
E)74 ^$\circ$ C

Question 30

Which of the following graphs shows the correct relationship between the pressure and volume of an ideal gas at a given temperature? Note the origin corresponds to P = 0 and V = 0.

A)
B)
C)
D)

Question 31

Which of the following is unimportant when using the ideal gas law?

A)the chemical identity of the gas sample
B)the temperature of the gas sample
C)the pressure of the gas sample
D)the volume of the container holding the gas sample
E)the amount of gas

Question 32

The temperature of a 10.0 g sample of Ne gas at a pressure of 1.6 atm is 17 ^$\circ$ C. What is the volume of the sample?

A)7.37 L
B)9.38 L
C)76.8 L
D)18.9 L
E)3.45 L

Question 33

A balloon vendor at a street fair is using a tank of helium to inflate the balloons. The tank has a volume of 75 L and a pressure of 95 atm at 22°C. The valve is not closed completely and some helium leaks out. After some time, the pressure drops to 85 atm. How many moles of helium have been lost?

A)0.90 mol
B)1.2 mol
C)73 mol
D)263 mol
E)31 mol

Question 34

If the pressure of a system is halved in a given volume, by what factor will the temperature change?

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

Question 35

A 25.0 L balloon is filled with 2.75 mol of helium. If the helium leaks out at the rate of 0.105 mol/hr, what is the volume of the balloon after 12.0 hr? Assume the pressure and temperature don't change.

A)11.5 L
B)13.5 L
C)23.7 L
D)1.26 L
E)17.4 L

Question 36

A sample of Ar gas at 35 ^$\circ$ C occupies a volume of 1.50 L at a pressure of 3.2 atm. How many moles of the gas are present in the sample?

A)3.32 moles
B)0.599 moles
C)5.26 moles
D)1.67 moles
E)0.190 moles

Question 37

Which of the following graphs shows the correct relationship between the pressure and temperature of an ideal gas in a given volume? Note the origin corresponds to P = 0 atm and T = 0 K.

A)
B)
C)
D)

Question 38

An unknown gas held in a 25.0 mL flask at 45°F exerts a pressure of 25 mtorr. Using this information with the ideal gas law, it is possible to determine ________

A)the mass of the gas in the container.
B)the identity of the gas in the container.
C)the number of molecules of the gas in the container.
D)the molecular geometry of the gas in the container.
E)nothing more about the gas.

Question 39

A hot air balloon, under the conditions shown below, experiences an increase in pressure. What will the new volume of the balloon be?

A)3.6 $\times$ 10^-2 L
B)12 L
C)28 L
D)40 L
E)250 L

Question 40

What is the volume of a gas that exerts a pressure of 457 mm Hg if it exerted a pressure of 2.50 atm when its volume was 25.0 mL?

A)9.62 mL
B)1.80 L
C)0.104 L
D)6.01 mL
E)25.0 L

Question 41

In an experiment, 7.5 mol of a gas are held in a 3.5 L container at 39 ^$\circ$ C. What pressure does the gas exert if it is assumed to be ideal?

A)5.5 atm
B)2.9 atm
C)6.9 atm
D)55 atm
E)96 atm

Question 42

Considering that PV = nRT, which one of these samples contains the largest number of particles? STP= 0 ^$\circ$ C and 1 atm.

A)2.0 L of H₂ at STP
B)2.0 L of N₂ at STP
C)2.0 L of H₂ at 25 ^$\circ$ C and 760 torr
D)2.0 L of N₂ at 0 ^$\circ$ C and 900 torr
E)2.0 L of He at STP

Question 43

Which of the following reactions will result in a reduced total pressure?

A)CH₄(g) 2O₂(g) CO₂(g) 2H₂O(g)
B)2N₂O(g) 2N₂(g) O₂(g)
C)2HI(g) H₂(g) I₂(g)
D)2H₂(g) O₂(g) 2H₂O(l )

Question 44

The pressure gauge on a 100-L cylinder used to fill balloons with helium shows a pressure of 1,470 psi at a temperature of 22^oC. How many kilograms of helium does the cylinder contain?

A)6.04 kg
B)1.65 kg
C)0.779 kg
D)4.30 kg
E)0.464 kg

Question 45

How many moles of propane are contained in a 5.00 L tank at 450 torr and 25 ^$\circ$ C?

A)0.12 mol
B)92 mol
C)1.4 mol
D)1,100 mol
E)41 mol

Question 46

What volume is occupied by 1.00 mol of an ideal gas at 1.00 atm and 0.00 ^$\circ$ C?

A)22.4 L
B)22.7 L
C)22.1 L
D)15.0 L
E)27.2 L

Question 47

Which one of these samples contains the smallest number of molecules?

A)1.0 L of H₂ at STP (0 ^$\circ$ C and 1 atm)
B)1.0 L of N₂ at STP
C)1.0 L of H₂ at 20 ^$\circ$ C and 760 torr
D)1.0 L of N₂ at 0 ^$\circ$ C and 800 torr
E)1.0 L of He at STP

Question 48

Calcium carbonate (100.1 g/mol) decomposes according to the following reaction equation: CaCO₃(s) CaO(s) CO₂(g)
What pressure of CO₂ gas will form in a 25.0 mL jar containing 5.00 g CaCO₃ at 300 K if 0.00500% of the solid decomposes?

A)0.246 atm
B)2.46 atm
C)1.00 atm
D)2.46 10³ atm
E)2.46 10^-3 atm

Question 49

Which of the following reactions will result in a negligible change in pressure?

A)Na(s) Cl₂(g) NaCl(s)
B)CO(g) H₂O(l ) CO₂(g) H₂(g)
C)CH₄(g) H₂O(l ) CO(g) 3H₂(g)
D)BrNO₂(g) NO(g) NO₂(g) BrNO(g)
E)2Na(s) 2H₂O(g) $\to$ 2NaOH(s) H₂(g)

Question 50

The pressure gauge on a cylinder used to fill balloons with He shows a pressure of 1,275 psi at a temperature of 25 ^$\circ$ C. Assuming the cylinder has a volume of 10 L, how many grams of He does the cylinder contain?

A)520 g
B)142 g
C)6.70 g
D)37.0 g
E)4.00 g

Question 51

What is the temperature if 3.0 g of propane (C₃H₈) in a 400.0 mL container exerts a pressure of 5.5 atm?

A)( 75.5 ^$\circ$ C)
B) ( 75.5 ^$\circ$ C)
C)121 ^$\circ$ C
D)175 ^$\circ$ C
E)264 ^$\circ$ C

Question 52

Which of the gas samples shown below in identical containers has the lowest density (g/L)?

A)
B)
C)
D)

Question 53

Considering that PV = nRT, which one of these samples contains the smallest number of particles?
STP = 0 ^$\circ$ C and 1 atm.

A)2.0 L of H₂ at STP
B)2.0 L of N₂ at STP
C)2.0 L of H₂ at 25 ^$\circ$ C and 760 torr
D)2.0 L of N₂ at 0 ^$\circ$ C and 900 torr
E)2.0 L of He at STP

Question 54

What is the pressure of a 0.17 mol sample of carbon monoxide gas contained in a 750mL flask at 50 ^$\circ$ C?

A)0.930 atm
B)6.01 atm
C)1.08 atm
D)0.166 atm
E)6.01 atm

Question 55

Automobile air bags inflate during a crash or sudden stop by the rapid generation of nitrogen gas from sodium azide. 2NaN₃(s) 2Na(s) 3N₂(g)
How many moles of sodium azide are needed to produce sufficient nitrogen to fill a 50.0 L air bag to a pressure of 1.25 atm at 25°C?

A)2.56 mol
B)3.83 mol
C)5.31 mol
D)1.70 mol
E)4.92 mol

Question 56

In an experiment, 25.0 mL of a gas with a pressure of 1.00 atm is contained in a balloon at 25.0°C. The balloon is then cooled to 5.0 ^$\circ$ C, and the pressure is found to be 0.750 atm. What is the volume of the gas under the new conditions?

A)17.5 mL
B)20.1 mL
C)25.0 mL
D)31.1 mL
E)35.7 mL

Question 57

A 22.4-L sealed chamber at 273 K is filled with air at a pressure of 1.00 atm. A solid state chemical reaction in the chamber adds 1.25 mol hydrogen gas. The temperature of the chamber must be decreased to ________ to maintain the pressure at 1.00 atm.

A)121 K
B)218 K
C)12.2 K
D)182 K
E)211 K

Question 58

In the presence of a catalyst, potassium chlorate decomposes and provides a very simple way to generate oxygen via the following decomposition reaction: 2KClO₃(s) 3O₂(g) 2KCl(s)
How many grams of potassium chlorate are needed to produce 38.2 L of oxygen gas at a pressure of 2.00 atm at a temperature of 310 K?

A)10.7 g
B)245 g
C)157 g
D)423 g
E)61.7 g

Question 59

Which of the gas samples shown below in identical containers has the highest density (g/L)?

A)
B)
C)
D)

Question 60

Which of the following reactions will result in an increased total pressure?

A)ClNO₂(g) NO(g) NO₂(g) ClNO(g)
B)CO(g) Cl₂(g) COCl₂(g)
C)N₂O₄(g) 2NO₂(g)
D)2H₂(g) O₂(g) 2H₂O(l )
E)CO₂(g) CF₄(g) 2COF₂(g)

Question 61

Indicate the gas with the lowest density at STP.

A)CH₄
B)F₂
C)N₂O
D)Cl₂
E)N₂

Question 62

Which of the following graphs shows how the density of an ideal gas changes with pressure?

A)
B)
C)
D)

Question 63

What is the temperature of CO₂ gas (density = 2.62 g/L) at a pressure of 3.0 atm?

A)253 ^$\circ$ C
B)195 ^$\circ$ C
C)341 ^$\circ$ C
D)614 ^$\circ$ C
E)468 ^$\circ$ C

Question 64

When a certain acid and a certain base are mixed together, a reaction occurs that produces a gas as one of the products. The gas has a density of 2.62 g/L at 1.47 atm and 27 ^$\circ$ C. What are the molar mass and identity of the gas?

A)H₂, 2 g/mol
B)CO, 28 g/mol
C)O₂, 32 g/mol
D)CO₂, 44 g/mol
E)SO₂, 64 g/mol

Question 65

Nitrous oxide (N₂O, also known as laughing gas) has been used as an anesthetic. What is the density of N₂O at 750 torr and 30 ^$\circ$ C?

A)1.2 g/L
B)1.1 g/L
C)1.9 g/L
D)1.7 g/L
E)1.5 g/L

Question 66

What is the molar mass of a gas that has a density of 2.62 g/L at 2.00 atm and 25.0 ^$\circ$ C?

A)32.0 g/mol
B)16.0 g/mol
C)64.0 g/mol
D)28.0 g/mol
E)2.69 g/mol

Question 67

What is the density of propane gas (CH₃CH₂CH₃, 44.1 g/mol) at 25 ^$\circ$ C and 650 mm Hg?

A)1.54 g/L
B)3.55 g/mL
C)18.3 g/L
D)2.05 g/L
E)1.17 g/L

Question 68

When a certain acid and a certain base are mixed together, a reaction occurs that produces a gas as one of the products. The gas has a density of 1.83 g/L at 1.00 atm and 20 ^$\circ$ C. What are the molar mass and identity of the gas?

A)H₂, 2 g/mol
B)CO, 28 g/mol
C)O₂, 32 g/mol
D)CO₂, 44 g/mol
E)SO₂, 64 g/mol

Question 69

Potassium superoxide reacts violently with water to produce potassium hydroxide and oxygen according to the following balanced equation. What would the temperature be if 5.0 g of KO₂ reacts to produce a pressure of 1.0 atm and 2.0 L of O₂ gas?

4KO₂(s) 2H₂O(l) 4KOH(s) 3O₂(g)

A)150 ^$\circ$ C
B)30 ^$\circ$ C
C) - 12 ^$\circ$ C
D)190 ^$\circ$ C
E)74 ^$\circ$ C

Question 70

The density of a pure gas at STP depends on its ________

A)molar mass.
B)concentration.
C)temperature.
D)volume.
E)pressure.

Question 71

Indicate the gas with the greatest density at STP.

A)CH₄
B)He
C)Ar
D)H₂
E)O₂

Question 72

What is the pressure of NO gas (density 1.34 g/L) at 25 ^$\circ$ C?

A)0.916 atm
B)1.09 atm
C)32.8 atm
D)9.16 atm
E)10.9 atm

Question 73

Which of the following samples of an ideal gas has the lowest density?

A)
B)
C)
D)

Question 74

Which one of the following gases could most easily be differentiated from propane (CH₃CH₂CH₃) on the basis of density when compared at the same temperature and pressure?

A)CO₂
B)N₂O
C)NO₂
D)F₂
E)CH₂ CH-CH₃

Question 75

Oxygen for astronauts in space can be produced chemically using a solid fuel oxygen generator. The reaction takes place at 600 ^$\circ$ C and is shown below. NaClO₃(s) Fe(s) 3O₂(g) NaCl(s) FeO(s)
What volume of O₂ gas will be produced when 855 g of NaClO₃ reacts with excess iron at a pressure of 3 atm?

A)575 L
B)2.80 L
C)192 L
D)6.13 L
E)396 L

Question 76

Poisonous carbon monoxide can be produced by furnaces in basements if the combustion and exhaust are not complete. Calculate the density of carbon monoxide in g/L at 292 K and 1.00 atm of pressure to determine whether it is more or less dense than air. If it is more dense, it will remain in the basement; if it is less dense it will rise to the upper levels of the house. The density of dry air is 1.20 g/L.

A)1.14 g/L
B)1.17 g/L
C)1.20 g/L
D)1.23 g/L
E)1.26 g/L

Question 77

Which of the following graphs shows how the density of an ideal gas changes with temperature?

A)
B)
C)
D)

Question 78

Which of the following gases has nearly the same density as CO₂ at room temperature and atmospheric pressure?

A)N₂
B)O₂
C)N₂O
D)Ar
E)CO

Question 79

The density of a gaseous compound of nitrogen and oxygen is 4.11 g/L at STP. What is the most likely formula of this gas?

A)N₂O₄
B)N₂O₅
C)N₂O
D)NO₂
E)NO

Question 80

The density of an unknown gas is 1.72 g/L at 750.0 torr and 30.0 ^$\circ$ C. Which of the following could be the unknown gas?

A)CS₂
B)NO
C)N₂O
D)NH₃
E)NO₂