Question 1

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

Accepted Answer

A)   O2
B)   CO2
C)   H2O
D)   H2
E)   All have the same average kinetic energy.F) B) and D)
G) A) and E)

Question 2

A gas consists of 85.7 % carbon and 14.3% hydrogen, by weight. A sample of this gas weighing 0.673 g occupies 729 mL at a pressure of 720.0 mmHg and a temperature of 77 °\degree° C. Calculate its empirical and molecular formulas.

Accepted Answer

A)   CH, C2H2
B)   CH2, C2H4
C)   CH2, C3H6
D)   CH3, C2H6
E)   CH4, CH4 F) A) and E)
G) D) and E)

Question 3

The ozone layer is important because

Accepted Answer

A)   ozone absorbs low energy radiation which warms the troposphere.
B)   ozone purifies the atmosphere by reacting with excess fluorocarbons.
C)   ozone absorbs ultraviolet radiation.
D)   ozone reflects high energy radiation such as X-rays and gamma rays.
E)   humans need to breathe air containing some ozone.F) All of the above
G) A) and B)

Question 4

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 E)
G) A) and B)

Question 5

. If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr?

Accepted Answer

A)   80.0 torr
B)   200. torr
C)   256 torr
D)   500. torr
E)   556 torrF) A) and C)
G) B) and C)

Question 6

For a gas obeying Charles's Law, a plot of V versus 1/T will give a straight line passing through the origin.

Accepted Answer

A) True 
 B)False

Question 7

A flask with a volume of 3.16 L contains 9.33 grams of an unknown gas at 32.0 °\degree° C and 1.00 atm. What is the molar mass of the gas?

Accepted Answer

A)   7.76 g/mol
B)   66.1 g/mol
C)   74.0 g/mol
D)   81.4 g/mol
E)   144 g/mol F) A) and E)
G) B) and C)

Question 8

A flask containing argon gas is connected to an closed-ended mercury manometer. The closed end is under vacuum. If the mercury level in the closed arm is 230. mm above that in the arm connected to the flask, what is the argon pressure, in torr?

Accepted Answer

A)   -230.
B)   230.
C)   530.
D)   790.
E)   None of these choices is correct.F) D) and E)
G) B) and C)

Question 9

Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25 °\degree° C and 753 torr. What mass of hydrogen was collected? (Pwater = 24 torr at 25 °\degree° C)

Accepted Answer

A)   0.00765 g
B)   0.0154 g
C)   0.0159 g
D)   0.0164 g
E)   0.159 g F) A) and B)
G) A) and C)

Question 10

State Amontons's Law and illustrate it with a graph, using standard x-y coordinate axes. Be sure to label the axes unambiguously with the correct gas variables.

Accepted Answer

At constant volume, the pressure of a fi...

Question 11

"The rate of effusion of a gas is inversely proportional to the square root of its molar mass" is a statement of ______________________ Law.

Accepted Answer

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

Question 12

The ideal gas law tends to become inaccurate when

Accepted Answer

A)   the pressure is lowered and molecular interactions become significant.
B)   the pressure is raised and the temperature is lowered.
C)   the temperature is raised above the temperature of STP.
D)   large gas samples are involved.
E)   the volume expands beyond the standard molar volume.F) C) and E)
G) A) and B)

Question 13

State Avogadro's Law.

Accepted Answer

Equal volumes of gas...

Question 14

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)   CHCl3
B)   CH2Cl2
C)   C2H2Cl2
D)   C2H3Cl
E)   CCl4F) B) and C)
G) None of the above

Question 15

According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average kinetic energy.

Accepted Answer

A) True 
 B)False

Question 16

A sample of oxygen gas has its absolute temperature halved while the pressure of the gas remained constant. If the initial volume is 400 mL, what is the final volume?

Accepted Answer

A)   20 mL
B)   133 mL
C)   200 mL
D)   400 mL
E)   800 mLF) B) and E)
G) A) and C)

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) None of the above
G) A) and D)

Question 18

A carbon dioxide sample weighing 44.0 g occupies 32.68 L at 65 °\degree° 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 L F) All of the above
G) A) and B)

Question 19

Use the van der Waals equation for real gases to calculate the pressure exerted by 1.00 mole of ammonia at 27 °\degree° C in a 750-mL container. (a = 4.17 L2*atm/mol2, b = 0.0371 L/mol)

Accepted Answer

A)   23.2 atm
B)   27.1 atm
C)   32.8 atm
D)   42.0 atm
E)   32.8 torr F) None of the above
G) All of the above

Question 20

The rate of diffusion of a gas is inversely proportional to its molar mass.

Accepted Answer

A) True 
 B)False

Exam 5: Gases and the Kinetic-Molecular Theory

For a gas obeying Charles's Law, a plot of V versus 1/T will give a straight line passing through the origin.

Correct AnswerverifiedShow Answer

The rate of diffusion of a gas is inversely proportional to its molar mass.

Correct AnswerverifiedShow Answer

According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average kinetic energy.

Correct AnswerverifiedShow Answer

Use the van der Waals equation for real gases to calculate the pressure exerted by 1.00 mole of ammonia at 27 °\degree° C in a 750-mL container. (a = 4.17 L2*atm/mol2, b = 0.0371 L/mol)

Correct AnswerverifiedShow Answer

The ozone layer is important because

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

"The rate of effusion of a gas is inversely proportional to the square root of its molar mass" is a statement of ______________________ Law.

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

State Avogadro's Law.

Correct AnswerverifiedEqual volumes of gas...View AnswerShow Answer

State Amontons's Law and illustrate it with a graph, using standard x-y coordinate axes. Be sure to label the axes unambiguously with the correct gas variables.

Correct AnswerverifiedAt constant volume, the pressure of a fi...View AnswerShow Answer

A flask containing argon gas is connected to an closed-ended mercury manometer. The closed end is under vacuum. If the mercury level in the closed arm is 230. mm above that in the arm connected to the flask, what is the argon pressure, in torr?

Correct AnswerverifiedShow Answer

A sample of oxygen gas has its absolute temperature halved while the pressure of the gas remained constant. If the initial volume is 400 mL, what is the final volume?

Correct AnswerverifiedShow Answer

The ideal gas law tends to become inaccurate when

Correct AnswerverifiedShow Answer

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

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

A gas consists of 85.7 % carbon and 14.3% hydrogen, by weight. A sample of this gas weighing 0.673 g occupies 729 mL at a pressure of 720.0 mmHg and a temperature of 77 °\degree° C. Calculate its empirical and molecular formulas.

Correct AnswerverifiedShow Answer

. If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr?

Correct AnswerverifiedShow Answer

Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25 °\degree° C and 753 torr. What mass of hydrogen was collected? (Pwater = 24 torr at 25 °\degree° C)

Correct AnswerverifiedShow Answer

A flask with a volume of 3.16 L contains 9.33 grams of an unknown gas at 32.0 °\degree° C and 1.00 atm. What is the molar mass of the gas?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Use the van der Waals equation for real gases to calculate the pressure exerted by 1.00 mole of ammonia at 27 $\degree$ C in a 750-mL container. (a = 4.17 L²*atm/mol², b = 0.0371 L/mol)

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Equal volumes of gas...
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Correct Answer
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At constant volume, the pressure of a fi...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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A gas consists of 85.7 % carbon and 14.3% hydrogen, by weight. A sample of this gas weighing 0.673 g occupies 729 mL at a pressure of 720.0 mmHg and a temperature of 77 $\degree$ C. Calculate its empirical and molecular formulas.

Correct Answer
verified

Correct Answer
verified

Small quantities of hydrogen can be prepared by the addition of hydrochloric acid to zinc. A sample of 195 mL of hydrogen was collected over water at 25 $\degree$ C and 753 torr. What mass of hydrogen was collected? (P_water = 24 torr at 25 $\degree$ C)

Correct Answer
verified

A flask with a volume of 3.16 L contains 9.33 grams of an unknown gas at 32.0 $\degree$ C and 1.00 atm. What is the molar mass of the gas?

Correct Answer
verified

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

Correct Answer
verified