Question 1

Which one of the following statements is not correct?
In a sample of air at a given temperature ________

Accepted Answer

A)   the nitrogen and oxygen molecules have the same average kinetic energy.
B)   the nitrogen and oxygen molecules have the same average speed.
C)   some nitrogen molecules are moving slower than some oxygen molecules.
D)   some nitrogen molecules are moving faster than some oxygen molecules.
E)   all the molecules are moving.

Question 2

Which set of gases is listed from slowest to fastest effusion rate?

Accepted Answer

A)   N2O 2 2O4
B)   NO 2O 2 2O4
C)   N2O4 2 2O 
D)   NO 2 2O 2O4
E)   N2O4 2O 2 < NO

Question 3

He and O2 gases are mixed at the Maui Dive Shop. A 40 L He cylinder with 10.0 atm pressure is connected to a 10 L O2 cylinder with 5.0 atm pressure. The valve between them is opened and the gases completely mix. The final pressure is ________, and the mole fraction of O2 is ________.

Accepted Answer

Question 4

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.

Accepted Answer

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

Question 5

The diffusion rate of H2 in a lecture hall was found to be 25.0 m/sec at 25°C. How long will it take poisonous HCN gas to diffuse 10 m in the same room?

Accepted Answer

A)   1.5 s
B)   0.11 s
C)   5.4 s
D)   0.19 s
E)   2.7 s

Question 6

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 1.00 atm and 25°C. What is the molar mass and identity of the gas?

Accepted Answer

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 7

In terms of the kinetic molecular theory, gases exert pressure due to ________

Accepted Answer

collisions of molecu...

Question 8

Determine the root-mean-square speed of methane (CH4)  molecules that have an average kinetic energy of 10.5 J/mol.

Accepted Answer

A)   337 m/s
B)   1.14 m/s
C)   2.81 * 1013 m/s
D)   36.2 m/s
E)   1,150 m/s

Question 9

Which one of the following statements is not a postulate of the kinetic molecular theory?

Accepted Answer

A)   The size of a molecule is negligible.
B)   Gas molecules move constantly and randomly throughout the space they occupy.
C)   The average kinetic energy of a gas molecule is directly proportional to the absolute temperature of the gas.
D)   Collisions of gas molecules with each other and with the walls of the container are elastic.
E)   Gas molecules attract and repel each other.

Question 10

In which of the following containers is the mole fraction of argon greatest? The white circles represent helium atoms; the dark circles represent argon atoms.

Accepted Answer

A)   
B)   
C)   
D)

Question 11

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

Accepted Answer

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

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 A =   π\piπ  r2 and that 1 N = 1 kg m/s2.

Accepted Answer

A)   3.183 * 104 Pa
B)   1.273 * 105 Pa
C)   3.183 *10-2 Pa
D)   1.273*10-2 Pa

Question 13

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.

Accepted Answer

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

Question 14

Which of the following graphs shows the correct relationship between pressure and volume for n moles of gas at temperature T?

Accepted Answer

A)   
B)   
C)   
D)

Question 15

During the decomposition of CaCO3(s)  into CaO(s)  and O2(g) , 100.0 mL of gas is collected by the displacement of water in a flask at 25°C with an atmospheric pressure of 755 mm Hg. The vapor pressure of water at this temperature is 23.8 mm Hg. What mass of oxygen was collected?

Accepted Answer

A)   0.679 mg
B)   21.7 mg
C)   12.9 mg
D)   0.807 mg
E)   126 mg

Question 16

The van der Waals equation for real gases contains an a parameter and a b parameter. Which statement about these parameters is not correct?

Accepted Answer

A)   One of these parameters accounts for the fact that the molecules occupy space and thereby reduce the free volume of the container.
B)   One of these parameters accounts for the fact that attractive forces between the molecules serve to reduce the pressure exerted on the walls of the container.
C)   The van der Waals equation is defined so both of these parameters have positive values.
D)   Both of these parameters increase with increasing number of atoms in each molecule.
E)   One of these parameters decreases with increasing mass of the molecules.

Question 17

The kinetic theory of gases assumes that collisions ________

Accepted Answer

A)   with the walls of the container cause energy to be lost.
B)   of molecules with each other cause energy to be lost.
C)   are caused by molecules attracting each other.
D)   do not result in a change in the energy of the molecules.
E)   do not occur because the size of the molecules is negligible.

Question 18

Explain why the constants a and b in the van der Waals equation for the noble gas elements increase with increasing atomic number.

Accepted Answer

The atoms become larger and mo...

Question 19

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

Accepted Answer

A)   
B)   
C)   
D)

Question 20

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

Accepted Answer

A)   
B)   
C)   
D)

Exam 6: Properties of Gases: the Air We Breathe

Which set of gases is listed from slowest to fastest effusion rate?

Correct AnswerverifiedShow Answer

In terms of the kinetic molecular theory, gases exert pressure due to ________

Correct Answerverifiedcollisions of molecu...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

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 1.00 atm and 25°C. What is the molar mass and identity of the gas?

Correct AnswerverifiedShow Answer

The kinetic theory of gases assumes that collisions ________

Correct AnswerverifiedShow Answer

Which one of the following statements is not correct? In a sample of air at a given temperature ________

Correct AnswerverifiedShow Answer

Determine the root-mean-square speed of methane (CH4) molecules that have an average kinetic energy of 10.5 J/mol.

Correct AnswerverifiedShow Answer

The van der Waals equation for real gases contains an a parameter and a b parameter. Which statement about these parameters is not correct?

Correct AnswerverifiedShow Answer

Which of the following graphs shows the correct relationship between pressure and volume for n moles of gas at temperature T?

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which one of the following statements is not a postulate of the kinetic molecular theory?

Correct AnswerverifiedShow Answer

During the decomposition of CaCO3(s) into CaO(s) and O2(g) , 100.0 mL of gas is collected by the displacement of water in a flask at 25°C with an atmospheric pressure of 755 mm Hg. The vapor pressure of water at this temperature is 23.8 mm Hg. What mass of oxygen was collected?

Correct AnswerverifiedShow Answer

Explain why the constants a and b in the van der Waals equation for the noble gas elements increase with increasing atomic number.

Correct AnswerverifiedThe atoms become larger and mo...View AnswerShow Answer

In which of the following containers is the mole fraction of argon greatest? The white circles represent helium atoms; the dark circles represent argon atoms.

Correct AnswerverifiedShow Answer

He and O2 gases are mixed at the Maui Dive Shop. A 40 L He cylinder with 10.0 atm pressure is connected to a 10 L O2 cylinder with 5.0 atm pressure. The valve between them is opened and the gases completely mix. The final pressure is ________, and the mole fraction of O2 is ________.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The diffusion rate of H2 in a lecture hall was found to be 25.0 m/sec at 25°C. How long will it take poisonous HCN gas to diffuse 10 m in the same room?

Correct AnswerverifiedShow Answer

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 A = π\piπ r2 and that 1 N = 1 kg m/s2.

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

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collisions of molecu...
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Determine the root-mean-square speed of methane (CH₄) molecules that have an average kinetic energy of 10.5 J/mol.

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Correct Answer
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During the decomposition of CaCO₃(s) into CaO(s) and O₂(g) , 100.0 mL of gas is collected by the displacement of water in a flask at 25°C with an atmospheric pressure of 755 mm Hg. The vapor pressure of water at this temperature is 23.8 mm Hg. What mass of oxygen was collected?

Correct Answer
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Correct Answer
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The atoms become larger and mo...
View Answer

Correct Answer
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He and O₂ gases are mixed at the Maui Dive Shop. A 40 L He cylinder with 10.0 atm pressure is connected to a 10 L O₂ cylinder with 5.0 atm pressure. The valve between them is opened and the gases completely mix. The final pressure is , and the mole fraction of O₂ is .

Correct Answer
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Correct Answer
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The diffusion rate of H₂ in a lecture hall was found to be 25.0 m/sec at 25°C. How long will it take poisonous HCN gas to diffuse 10 m in the same room?

Correct Answer
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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 A = $\pi$ r² and that 1 N = 1 kg m/s².

Correct Answer
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Correct Answer
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