Holt: Modern Chemistry

Mickey Sarquis, Jerry L. Sarquis

Chapter 11

Gases - all with Video Answers

Educators

+ 14 more educators

Chapter Questions

Problem 1

State the assumptions that the kinetic-molecular theory makes about the characteristics of gas particles.

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 2

What is an ideal gas?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 3

a. Why does a gas in a closed container exert pressure?
b. What is the relationship between the area a force is applied to and the resulting pressure?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 4

a. Why does a column of mercury in a tube that is inverted in a dish of mercury have a height of about 760 mm at sea level?
b. The density of water is approximately 1/13.5 the density of mercury. What height would be maintained by a column of water inverted in a dish of water at sea level?
c. What accounts for the difference in the heights of the mercury and water columns?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 5

a. Identify three units used to express pressure.
b. Convert one atmosphere to millimeters of mercury.
c. What is a pascal?
d. What is the SI equivalent of one standard atmosphere of pressure?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 6

a. Explain what is meant by the partial pressure of each gas within a mixture of gases.
b. How do the partial pressures of gases in a mixture affect each other?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 7

If the atmosphere can support a column of mercury 760 mm high at sea level, what height of a hypothetical liquid whose density is 1.40 times the density of mercury could be supported?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 8

Convert each of the following into a pressure reading expressed in torrs.

a. 1.25 $atm$
b. $2.48 \times 10^{-3} atm$
c. $4.75 \times 10^{4} atm$
d. $7.60 \times 10^{6} atm$

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 9

Convert each of the following into the unit specified.

a. 125 mm Hg into atmospheres
b. 3.20 atm into pascals
c. 5.38 kPa into millimeters of mercury

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 10

Three of the primary components of air are carbon dioxide, nitrogen, and oxygen. In a sample containing a mixture of only these gases at exactly 1 atm, the partial pressures of carbon dioxide and nitrogen are given as $P_{CO{2}}=0.285$ torr and $P_{N_{2}}=593.525$ torr. What is the partial pressure of oxygen?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 11

A gas sample is collected over water at a temperature of 35.0°C when the barometric pressure reading is 742.0 torr. What is the partial pressure of the dry gas?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 12

How are the volume and pressure of a gas at constant temperature related?

Ronald Prasad

Numerade Educator

Problem 13

Explain why pressure increases as a gas is compressed into a smaller volume.

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 14

How are the absolute temperature and volume of a gas at constant pressure related?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 15

How are the pressure and absolute temperature of a gas at constant volume related?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 16

Explain Gay-Lussac’s law in terms of the kinetic- molecular theory.

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 17

State the combined gas law.

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 18

Use Boyle’s law to solve for the missing value in each of the following:

a. $P_{1}=350.0$ torr, $V_{1}=200.0 mL, P_{2}=700.0$ torr,
$V_{2}=?$
b. $V_{1}=2.4 \times 10^{5} L, P_{2}=180 mm Hg$
$V_{2}=1.8 \times 10^{3} L, P_{1}=?$

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 19

Use Charles’s law to solve for the missing value in each of the following:

a. $V_{1}=80.0 mL, T_{1}=27^{\circ} C, T_{2}=77^{\circ} C, V_{2}=?$
b. $V_{1}=125 L, V_{2}=85.0 L, T_{2}=127^{\circ} C, T_{1}=?$
c. $T_{1}=-33^{\circ} C, V_{2}=54.0 mL T_{2}=160.0^{\circ} C, V_{1}=?$

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 20

A sample of air has a volume of 140.0 mL at 67°C. At what temperature would its volume be 50.0 mL at constant pressure?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 21

The pressure exerted on a 240.0 mL sample of hydrogen gas at constant temperature is increased from 0.428 atm to 0.724 atm. What will the final volume of the sample be?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 22

A sample of hydrogen at 47°C exerts a pressure of 0.329 atm. The gas is heated to 77°C at constant volume. What will its new pressure be?

Ronald Prasad

Numerade Educator

Problem 23

A sample of gas at 47°C and 1.03 atm occupies a volume of 2.20 L. What volume would this gas occupy at 107°C and 0.789 atm?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 24

The pressure on a gas at -73°C is doubled, but its volume is held constant. What will the final temperature be in degrees Celsius?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 25

A flask containing 155 $cm^{3}$ of hydrogen was collected under a pressure of 22.5 $kPa$ . What pressure would have been required for the volume of the gas to have been $90.0 cm^{3},$ assuming the same temperature?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 26

A gas has a volume of 450.0 mL. If the temperature is held constant, what volume would the gas occupy if the pressure were

a. doubled? (Hint: Express $P_{2}$ in terms of $P_{r}, )$
b. reduced to one-fourth of its original value?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 27

A sample of oxygen that occupies $1.00 \times 10^{6} mL$ at 575 $mm$ Hg is subjected to a pressure of 1.25 $atm$ . What will the final volume of the sample be if the temperature is held constant?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 28

To what temperature must a sample of nitrogen at 27°C and 0.625 atm be taken so that its pressure becomes 1.125 atm at constant volume?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 29

A gas has a volume of 1.75 L at -23°C and 150.0 kPa. At what temperature would the gas occupy 1.30 L at 210.0 kPa?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 30

A gas at $7.75 \times 10^{4}$ Pa and $17^{\circ}$ C occupies a volume of 850.0 $cm^{3} .$ At what temperature, in degrees Celsius, would the gas occupy 720.0 $cm^{3}$ at $8.10 \times 10^{4} Pa$ ?

Mehrnaz Siavoshi

Mehrnaz Siavoshi

Numerade Educator

Problem 31

A meteorological balloon contains 250.0 L He at 22°C and 740.0 mm Hg. If the volume of the balloon can vary according to external conditions, what volume would it occupy at an altitude at which the temperature is -52°C and the pressure is 0.750 atm?

HA

Halle Adair

Numerade Educator

Problem 32

The balloon in the previous problem will burst if its volume reaches 400.0 L. Given the initial conditions specified in that problem, determine at what temperature, in degrees Celsius, the balloon will burst if its pressure at that bursting point is 0.475 atm.

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 33

The normal respiratory rate for a human being is $15,0$ breaths per minute. The average volume of air for each breath is 505 $cm^{3}$ at $20.0^{\circ} C$ and $9.95 \times 10^{4} Pa$ . What is the volume of air at STP that an individual breathes in one day? Give your answer in cubic meters.

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 34

a. What are the restrictions on the use of Gay-Lussac’s law of combining volumes?
b. At the same temperature and pressure, what is the relationship between the volume of a gas and the number of molecules present?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 35

a. In a balanced chemical equation, what is the relationship between the molar ratios and the volume ratios of gaseous reactants and products?
b. What restriction applies to the use of the volume ratios in solving stoichiometry problems?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 36

According to Avogadro,
a. what is the relationship between gas volume and number of moles at constant temperature and pressure?
b. what is the mathematical expression denoting this relationship?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 37

What is the relationship between the number of molecules and the mass of 22.4 L of different gases at STP?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 38

a. In what situations is the ideal gas law most suitable for calculations?
b. When using this law, why do you have to pay particular attention to units?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 39

a. Write the equation for the ideal gas law.
b. What relationship is expressed in the ideal gas law?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 40

Suppose a 5.00 L sample of $O_{2}$ at a given temperature and pressure contains $1.08 \times 10^{23}$ molecules. How many molecules would be contained in each of the following at the same temperature and pressure?

a. 5.0 $LH_{2}$
b. 5.0 $LCO_{2}$
c. 10.0 $L NH_{3}$

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 41

How many moles are contained in each of the following at STP?

a. 22.4 $L N_{2}$
b. 5.60 $L Cl_{2}$
c. 0.125 $L Ne$
d. 70.0 $L NH_{3}$

David Collins

Numerade Educator

Problem 42

Find the mass, in grams, of each of the following at STP.

a. 11.2 $L H_{2}$
b. 2.80 $LCO_{2}$
c. 15.0 $mL SO_{2}$
d. 3.40 $cm^{3} F_{2}$

David Collins

Numerade Educator

Problem 43

Find the volume, in liters, of each of the following at STP.

a. 8.00 $g O_{2}$
b. 3.50 $g CO$
c. 0.0170 $g H_{2} S$
d. $2.25 \times 10^{5} kg NH_{3}$

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 44

Accetylene gas, $C_{2} H_{2},$ undergoes combustion to produce carbon dioxide and water vapor. If 75.0 $L$ $CO_{2}$ is produced,

a. how many liters of $C_{2} H_{2}$ are required?
b. what volume of $H_{2} O$ vapor is produced?
c. what volume of $O_{2}$ is required?

David Collins

Numerade Educator

Problem 45

Assume that 5.60 $LH_{2}$ at STP reacts with excess $CuO$ according to the following equation:
$$CuO(s)+H_{2}(g) \rightarrow Cu(s)+H_{2} O(g)$$
Make sure the equation is balanced before beginning your calculations.

a. How many moles of $H_{2}$ react?
b. How many moles of $Cu$ are produced?
c. How many grams of $Cu$ are produced?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 46

If 29.0 $L$ of methane, $CH_{4},$ undergoes complete combustion at 0.961 $\mathrm{atm}$ and $140^{\circ} C,$ how many liters of each product would be present at the same temperature and pressure?

David Collins

Numerade Educator

Problem 47

If air is 20.9$\%$ oxygen by volume,

a. how many liters of air are needed for complete combustion of 25.0 $L$ of octane vapor, $C_{8} H_{18}$ ?
b. what volume of each product is produced?

David Collins

Numerade Educator

Problem 48

Methanol, $CH_{3} OH,$ is made by causing carbon monoxide and hydrogen gases to react at high temperature and pressure. If $4.50 \times 10^{2} \mathrm{mL} CO$and $8.25 \times 10^{2} mL H_{2}$ are mixed,

a. which reactant is present in excess?
b. how much of that reactant remains after the reaction?
c. what volume of $CH_{3} OH$ is produced, assuming the same pressure?

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 49

Calculate the pressure, in atmospheres, exerted by each of the following:

a. 2.50 $L$ $HF$ containing 1.35 mol at 320.0 $K$
b. 4.75 $L NO_{2}$ containing 0.86 $\mathrm{mol}$ at 300.0 $K$
c. $5.50 \times 10^{4} \mathrm{mL} CO_{2}$ containing 2.15 $\mathrm{mol}$ at $57^{\circ} C$

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 50

Calculate the volume, in liters, occupied by each of the following

a. 2.00 $mol H_{2}$ at 300.0 $K$ and 1.25 $\mathrm{atm}$
b. 0.425 $\mathrm{mol} NH_{3}$ at $37^{\circ} C$ and 0.724 $\mathrm{atm}$
c. 4.00 $\mathrm{g} O_{2}$ at $57^{\circ} C$ and 0.888 $\mathrm{atm}$

Jake Rempel

Numerade Educator

Problem 51

Determine the number of moles of gas contained in each of the following:

a. 1.25 L at 250.0 K and 1.06 atm
b. 0.80 L at 27°C and 0.925 atm
c. $7.50 \times 10^{2} mL$ at $-50.0^{\circ} C$ and 0.921 $atm$

David Collins

Numerade Educator

Problem 52

Find the mass of each of the following.

a. 5.60 $LO_{2}$ at 1.75 atm and 250.0 $K$
b. 3.50 $L NH_{3}$ at 0.921 $atm$ and $27^{\circ} C$
c. 125 $mL SO_{2}$ at 0.822 $atm$ and $-5^{\circ} C$

David Collins

Numerade Educator

Problem 53

Describe in your own words the process of diffusion.

Theodore Donnell

Theodore Donnell

Numerade Educator

Problem 54

At a given temperature, what factor determines the rates at which different molecules undergo diffusion and effusion?

David Collins

Numerade Educator

Problem 55

Ammonia, $NH_{3}$ and alcohol, $C_{2} H_{6} O,$ are released together across a room. Which will you smell first?

Theodore Donnell

Theodore Donnell

Numerade Educator

Problem 56

Quantitatively compare the rates of effusion for the following pairs of gases at the same temperature and pressure:

a. hydrogen and nitrogen
b. fluorine and chlorine

David Collins

Numerade Educator

Problem 57

What is the ratio of the average velocity of hydrogen molecules to that of neon atoms at the same temperature and pressure?

Shahina -

Numerade Educator

Problem 58

At a certain temperature and pressure, chlorine molecules have an average velocity of 324 m/s. What is the average velocity of sulfur dioxide molecules under the same conditions?

Ronald Prasad

Numerade Educator

Problem 59

A mixture of three gases, A, B, and C, is at a total pressure of 6.11 atm. The partial pressure of gas A is 1.68 atm; that of gas B is 3.89 atm. What is the partial pressure of gas C?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 60

A child receives a balloon filled with 2.30 L of helium from a vendor at an amusement park. The temperature outside is 311 K. What will the volume of the balloon be when the child brings it home to an air-conditioned house at 295 K? Assume that the pressure stays the same.

David Collins

Numerade Educator

Problem 61

A sample of argon gas occupies a volume of 295 mL at 36°C. What volume will the gas occupy at 55°C, assuming constant pressure?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 62

A sample of carbon dioxide gas occupies 638 mL at 0.893 atm and 12°C. What will the pressure be at a volume of 881 mL and a temperature of 18°C?

David Collins

Numerade Educator

Problem 63

At 84°C, a gas in a container exerts a pressure of 0.503 atm. Assuming the size of the container has not changed, at what temperature in Celsius degrees would the pressure be 1.20 atm?

Anand Jangid

Numerade Educator

Problem 64

A weather balloon at Earth’s surface has a volume of 4.00 L at 304 K and 755 mm Hg. If the balloon is released and the volume reaches 4.08 L at 728 mm Hg, what is the temperature?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 65

A gas has a pressure of 4.62 atm when its volume is 2.33 L. If the temperature remains constant, what will the pressure be when the volume is changed to 1.03 L? Express the final pressure in torrs.

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 66

At a deep-sea station that is 200 m below the surface of the Pacific Ocean, workers live in a highly pressurized environment. How many liters of gas at STP must be compressed on the surface to fill the underwater environment with $2.00 \times 10^{7} L$ of gas at 20.0 atm? Assume that temperature remains constant.

David Collins

Numerade Educator

Problem 67

An unknown gas effuses at 0.850 times the effusion rate of nitrogen dioxide, $NO_{2}.$ Estimate the molar mass of the unknown gas.

David Collins

Numerade Educator

Problem 68

A container holds 265 mL of chlorine gas, $Cl_{2}$. If the gas sample is at STP, what is its mass?

Kristen Justice

Kristen Justice

Numerade Educator

Problem 69

Suppose that 3.11 mol of carbon dioxide is at a pressure of 0.820 atm and a temperature of 39°C. What is the volume of the sample, in liters?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 70

Compare the rates of diffusion of carbon monoxide, $CO,$ and sulfur trioxide, $SO_{3}.$

David Collins

Numerade Educator

Problem 71

A gas sample that has a mass of 0.993 g occupies 0.570 L. Given that the temperature is 281 K and the pressure is 1.44 atm, what is the molar mass of the gas?

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 72

How many moles of helium gas would it take to fill a balloon with a volume of 1000.0 $cm^{3}$ when the temperature is $32^{\circ} C$ and the atmospheric pressure is 752 $mm$ Hg?

David Collins

Numerade Educator

Problem 73

A gas sample is collected at 16°C and 0.982 atm. If the sample has a mass of 7.40 g and a volume of 3.96 L, find the volume of the gas at STP and the molar mass.

David Collins

Numerade Educator

Problem 74

a. Why do we say the graph in Figure 2.2 illustrates an inverse relationship?
b. Why do we say the data plotted in Figure 2.4 indicate a direct relationship?

David Collins

Numerade Educator

Problem 75

If all gases behaved as ideal gases under all conditions of temperature and pressure, solid or liquid forms of these substances would not exist. Explain.

Kathleen Kozinski

Kathleen Kozinski

Numerade Educator

Problem 76

Pressure is defined as force per unit area. Yet Torricelli found that the diameter of the barometer dish and the surface area of contact between the mercury in the tube and in the dish did not affect the height of mercury that was supported. Explain this seemingly inconsistent observation in view of the relationship between pressure and surface area.

David Collins

Numerade Educator

Problem 77

In solving a problem, what types of conditions involving temperature, pressure, volume, or number of moles would allow you to use
a. the combined gas law?
b. the ideal gas law?

David Collins

Numerade Educator

Problem 78

Gay-Lussac’s law of combining volumes holds true for relative volumes at any proportionate size. Use Avogadro’s law to explain why this proportionality exists.

David Collins

Numerade Educator

Problem 79

The graph below shows velocity distribution curves for the same gas under two different conditions, A and B. Compare the behavior of the gas under conditions A and B in relation to each of the following:

a. temperature
b. average kinetic energy
c. average molecular velocity
d. gas volume
e. gas pressure

David Collins

Numerade Educator

Problem 80

The diagrams below represent equal volumes of four different gases. Use the diagrams to answer the following questions:

a. Are these gases at the same temperature and pressure? How do you know?
b. If the molar mass of gas B is 38 g/mol and that of gas C is 46 g/mol, which gas sample is denser?
c. To make the densities of gas samples B and C equal, which gas should expand in volume?
d. If the densities of gas samples A and C are equal, what is the relationship between their molar masses?

David Collins

Numerade Educator

Problem 81

Design and conduct a meteorological study to examine the interrelationships among barometric pressure, temperature, humidity, and other weather variables. Prepare a report explaining your results.

AG

Ankit Gupta

Numerade Educator

Problem 82

Conduct library research on attempts made to approach absolute zero and on the interesting properties that materials exhibit near that temperature. Write a report on your findings.

Jerrah Biggerstaff

Jerrah Biggerstaff

Numerade Educator

Problem 83

How do scuba divers use the laws and principles that describe the behavior of gases to their advantage? What precautions do they take to prevent the bends?

David Collins

Numerade Educator

Problem 84

Explain the processes involved in the liquefaction of gases. Name some substances that are gases under normal room conditions and that are typically used in the liquid form. Explain why this is so.

David Collins

Numerade Educator

Problem 85

Write a summary describing how Gay-Lussac’s work on combining volumes relates to Avogadro’s study of gases. Explain how certain conclusions about gases followed logically from consideration of the work of both scientists.

David Collins

Numerade Educator

Problem 86

Review the melting point data in the properties tables for each group of the Elements Handbook (Appendix A). What elements on the periodic table exist as gases at room temperature?

David Collins

Numerade Educator

Problem 87

Review in the Elements Handbook (Appendix A) the listing of the top 10 chemicals produced in the United States. Which of the top 10 chemicals are gases?

David Collins

Numerade Educator

Problem 88

Most elements from Groups 1, 2, and 13 will react water, acids, or bases to produce hydrogen gas. Review the common reactions information in the Elements Handbook (Appendix A) and answer the following questions:

a. What is the equation for the reaction of barium with water?
b. What is the equation for the reaction between cesium and hydrochloric acid?
c. What is the equation for the reaction of gallium with hydrofluoric acid?
d. What mass of barium would be needed to react with excess water to produce 10.1 $L H_{2}$ at $STP$ ?
e. What masses of cesium and hydrochloric acid would be required to produce 10.1 $L H_{2}$ at STP?

David Collins

Numerade Educator

Problem 89

Group 1 metals react with oxygen to produce oxides, peroxides, or superoxides. Review the equations for these common reactions in the Elements Handbook (Appendix A), and answer the following:

a. How do oxides, peroxides, and superoxides differ?
b. What mass of product will be formed from a reaction of $5.00 L O_{2}$ with excess sodium? The reaction occurs at 27°C and 1 atm.

Diana Sechniasvili

Diana Sechniasvili

Numerade Educator

Problem 90

The air pressure of car tires should be checked regularly for safety reasons and for prevention of uneven tire wear. Find out the units of measurement on a typical tire gauge, and determine how gauge pressure relates to atmospheric pressure.

David Collins

Numerade Educator

Problem 91

During a typical day, record every instance in which you encounter the diffusion or effusion of gases (for example, when smelling perfume).

Anna Miller

Numerade Educator

Problem 92

Qualitatively compare the molecular masses of various gases by noting how long it takes you to smell them from a fixed distance. Work only with materials that are not dangerous, such as flavor extracts, fruit peels, and onions.

David Collins

Numerade Educator

Problem 93

Design an experiment to gather data to verify the ideal gas law. If your teacher approves of your plan, carry it out. Illustrate your data with a graph, and determine if the data are consistent with the ideal gas law.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator