Question 1

Calculate the root-mean-square speed of methane, CH4 (g) , at 78°C.

Accepted Answer

A)  23 m/s
B)  350 m/s
C)  550 m/s
D)  667 m/s
E)  740 m/sF) B) and D)
G) A) and D)

Question 2

Mercury is 13.6 times as dense as liquid water. What would be the reading of a water-filled barometer at normal atmospheric pressure, 760. mmHg?

Accepted Answer

A)  1.03 × 10 3 torr
B)  1.03 × 10 3 Pa
C)  1.03 × 10 3 mm height of water column
D)  1.03 × 10 3 cm height of water column
E)  13.6 atmF) B) and E)
G) C) and D)

Question 3

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its pressure, other factors remaining constant?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) A) and B)
G) B) and E)

Question 4

Which of the following changes will not affect the total pressure of gas in a container, assuming all other factors remain constant?

Accepted Answer

A)  The frequency of collisions of molecules with the walls is increased.
B)  The average velocity of the molecules is lowered.
C)  The temperature of the sample is altered.
D)  Half of the molecules are replaced by an equal number of molecules of a gas with a different molecular weight.
E)  The total number of molecules is altered.F) A) and C)
G) C) and E)

Question 5

Select the gas with the largest root-mean-square molecular speed at 25°C.

Accepted Answer

A)  NH 3
B)  CO
C)  H 2
D)  SF 6
E)  All the gases have the same root-mean-square molecular speed at 25°C.F) D) and E)
G) A) and D)

Question 6

Linolenic acid (C18H30O2)  can be hydrogenated to stearic acid by reacting it with hydrogen gas according to the equation: C18H30O2 + 3H2 → C18H36O2
What volume of hydrogen gas, measured at STP, is required to react with 10.5 g of linolenic acid in this reaction?

Accepted Answer

A)  2.53 L
B)  1.69 L
C)  1.27 L
D)  845 mL
E)  422 mLF) B) and D)
G) C) and D)

Question 7

The pressure of hydrogen sulfide gas in a container is 35,650 Pa. What is this pressure in torr?

Accepted Answer

A)  46.91 torr
B)  267.4 torr
C)  351.8 torr
D)  3612 torr
E)  27090 torrF) None of the above
G) B) and C)

Question 8

A sample of propane, a component of LP gas, has a volume of 35.3 L at 315 K and 922 torr. What is its volume at STP?

Accepted Answer

A)  25.2 L
B)  30.6 L
C)  33.6 L
D)  37.1 L
E)  49.2 LF) All of the above
G) A) and D)

Question 9

A compound composed of carbon, hydrogen, and chlorine effuses through a pinhole 0.411 times as fast as neon. Select the correct molecular formula for the compound.

Accepted Answer

A)  CHCl 3
B)  CH 2Cl 2
C)  C 2H 2Cl 2
D)  C 2H 3Cl
E)  CCl 4F) B) and E)
G) B) and D)

Question 10

The air pressure in a volleyball is 75 psi. What is this pressure in torr?

Accepted Answer

A)  520 torr
B)  562 torr
C)  3900 torr
D)  7600 torr
E)  75000 torrF) None of the above
G) A) and B)

Question 11

Select the gas with the highest average kinetic energy per mole at 298 K.

Accepted Answer

A)  O 2
B)  CO 2
C)  H 2O
D)  H 2
E)  All have the same average kinetic energy.F) A) and B)
G) A) and C)

Question 12

At a temperature of absolute zero, the volume of an ideal gas is zero.

Accepted Answer

A) True 
 B)False

Question 13

Arrange the following gases in order of increasing rate of effusion. C2H6 Ar HCl PH3

Accepted Answer

A)  Ar 3 2H 6
B)  C 2H 6 3 
C)  Ar 3 2H 6 
D)  C 2H 6 3 
E)  Ar 32H 6F) All of the above
G) A) and E)

Question 14

An unknown liquid is vaporized in a 273-mL flask by immersion in a water bath at 99°C. The barometric pressure is 753 torr. If the mass of the vapor retained in the flask is 1.362 g, what is its molar mass?

Accepted Answer

A)  20.4 g/mol
B)  40.9 g/mol
C)  112 g/mol
D)  154 g/mol
E)  184 g/molF) A) and D)
G) C) and D)

Question 15

When a closed-ended manometer is used for pressure measurements, and the closed end is under vacuum, the level of manometer liquid in the closed arm can never be lower than that in the other arm.

Accepted Answer

A) True 
 B)False

Question 16

For real gases, PV > nRT, always.

Accepted Answer

A) True 
 B)False

Question 17

"The total pressure in a mixture of unreacting gases is equal to the sum of the partial pressures of the individual gases" is a statement of __________ Law.

Accepted Answer

A)  Charles's
B)  Graham's
C)  Boyle's
D)  Avogadro's
E)  Dalton'sF) B) and C)
G) D) and E)

Question 18

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of __________ Law.

Accepted Answer

A)  Charles's
B)  Boyle's
C)  Amontons's
D)  Avogadro's
E)  Dalton'sF) None of the above
G) C) and E)

Question 19

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its absolute temperature, other factors remaining constant?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) A) and C)
G) A) and E)

Question 20

A carbon dioxide sample weighing 44.0 g occupies 32.68 L at 65°C and 645 torr. What is its volume at STP?

Accepted Answer

A)  22.4 L
B)  31.1 L
C)  34.3 L
D)  35.2 L
E)  47.7 LF) C) and D)
G) B) and D)

Exam 5: Gases and the Kinetic-Molecular Theory

Which of the following changes will not affect the total pressure of gas in a container, assuming all other factors remain constant?

Correct AnswerverifiedShow Answer

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of __________ Law.

Correct AnswerverifiedShow Answer

A carbon dioxide sample weighing 44.0 g occupies 32.68 L at 65°C and 645 torr. What is its volume at STP?

Correct AnswerverifiedShow Answer

The air pressure in a volleyball is 75 psi. What is this pressure in torr?

Correct AnswerverifiedShow Answer

An unknown liquid is vaporized in a 273-mL flask by immersion in a water bath at 99°C. The barometric pressure is 753 torr. If the mass of the vapor retained in the flask is 1.362 g, what is its molar mass?

Correct AnswerverifiedShow Answer

"The total pressure in a mixture of unreacting gases is equal to the sum of the partial pressures of the individual gases" is a statement of __________ Law.

Correct AnswerverifiedShow Answer

Calculate the root-mean-square speed of methane, CH4 (g) , at 78°C.

Correct AnswerverifiedShow Answer

When a closed-ended manometer is used for pressure measurements, and the closed end is under vacuum, the level of manometer liquid in the closed arm can never be lower than that in the other arm.

Correct AnswerverifiedShow Answer

At a temperature of absolute zero, the volume of an ideal gas is zero.

Correct AnswerverifiedShow Answer

Select the gas with the largest root-mean-square molecular speed at 25°C.

Correct AnswerverifiedShow Answer

Mercury is 13.6 times as dense as liquid water. What would be the reading of a water-filled barometer at normal atmospheric pressure, 760. mmHg?

Correct AnswerverifiedShow Answer

Linolenic acid (C18H30O2) can be hydrogenated to stearic acid by reacting it with hydrogen gas according to the equation: C18H30O2 + 3H2 → C18H36O2 What volume of hydrogen gas, measured at STP, is required to react with 10.5 g of linolenic acid in this reaction?

Correct AnswerverifiedShow Answer

The pressure of hydrogen sulfide gas in a container is 35,650 Pa. What is this pressure in torr?

Correct AnswerverifiedShow Answer

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its absolute temperature, other factors remaining constant?

Correct AnswerverifiedShow Answer

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its pressure, other factors remaining constant?

Correct AnswerverifiedShow Answer

A compound composed of carbon, hydrogen, and chlorine effuses through a pinhole 0.411 times as fast as neon. Select the correct molecular formula for the compound.

Correct AnswerverifiedShow Answer

Select the gas with the highest average kinetic energy per mole at 298 K.

Correct AnswerverifiedShow Answer

For real gases, PV > nRT, always.

Correct AnswerverifiedShow Answer

A sample of propane, a component of LP gas, has a volume of 35.3 L at 315 K and 922 torr. What is its volume at STP?

Correct AnswerverifiedShow Answer

Arrange the following gases in order of increasing rate of effusion. C2H6 Ar HCl PH3

Correct AnswerverifiedShow Answer

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Calculate the root-mean-square speed of methane, CH₄(g) , at 78°C.

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Linolenic acid (C₁₈H₃₀O₂) can be hydrogenated to stearic acid by reacting it with hydrogen gas according to the equation: C₁₈H₃₀O₂ + 3H₂ → C₁₈H₃₆O₂ What volume of hydrogen gas, measured at STP, is required to react with 10.5 g of linolenic acid in this reaction?

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Arrange the following gases in order of increasing rate of effusion. C₂H₆Ar HCl PH₃

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