Question 1

A 3.0-L sample of helium was placed in container fitted with a porous membrane. Half of the helium effused through the membrane in 24 hours. A 3.0-L sample of oxygen was placed in an identical container. How many hours will it take for half of the oxygen to effuse through the membrane?

Accepted Answer

A)   8.5 h
B)   12 h
C)   48 h
D)   60. h
E)   68 h E

Question 2

What is the density of Ar(g) at -11°C and 675 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

Accepted Answer

A)   1.52 g/L
B)   1.65 g/L
C)   -39.3 g/L
D)   40.0 g/L
E)   1.25 kg/L B

Question 3

If the atmospheric pressure in Denver is 0.8800 atm, what is this pressure expressed in mmHg? (1 atm = 101,325 Pa = 760 torr, 1 torr = 1 mmHg)?

Accepted Answer

A)   151.5 mmHg
B)   1.16 × 10-3 mmHg
C)   863.6 mmHg
D)   8.92 × 104 mmHg
E)   668.8 mmHg E

Question 4

Deviations from the ideal gas law are greater at

Accepted Answer

A)   low temperatures and low pressures.
B)   low temperatures and high pressures.
C)   high temperatures and high pressures.
D)   high temperatures and low pressures.

Question 5

A sample of N2 gas occupies 2.40 L at 20°C. At what temperature will the N2 gas occupy a volume of 4.80 L at constant pressure?

Accepted Answer

A)   10°C
B)   40°C
C)   146°C
D)   313°C
E)   586°C

Question 6

Freon-12, CF2Cl2, which has been widely used in air conditioning systems, is considered a threat to the ozone layer in the stratosphere. Calculate the root-mean-square velocity of Freon-12 molecules in the lower stratosphere where the temperature is -65°C.

Accepted Answer

A)   20 m/s
B)   120 m/s
C)   207 m/s
D)   260 m/s
E)   4.4 × 104 m/s

Question 7

What are the units of the constant a in the van der Waals equation?

Accepted Answer

A)   L/mol
B)   atm
C)   L • atm/K • mol
D)   L2 • atm/mol2

Question 8

A 250.0-mL sample of ammonia, NH3(g), exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

Accepted Answer

A)   0.0787 g
B)   0.180 g
C)   8.04 g
D)   17.0 g
E)   59.8 g

Question 9

Explain why you do not feel atmospheric pressure pushing on your body.

Accepted Answer

The answer of Explain why you do not feel atmospheric...

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

What is the temperature in Celsius at 4 K, which is the normal boiling point of liquid helium?

Accepted Answer

A)   -269°C
B)   269°C
C)   277°C
D)   68.3°C
E)   -277°C

Question 12

A flask containing argon gas is connected to a 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. torr
B)   230. torr
C)   530. torr
D)   790. torr
E)   990. torr

Question 13

Nitrogen will behave most like an ideal gas

Accepted Answer

A)   at high temperature and high pressure.
B)   at high temperature and low pressure.
C)   at low temperature and high pressure.
D)   at low temperature and low pressure.
E)   at intermediate (moderate)  temperature and pressure.

Question 14

A sample of nitrogen gas at 298 K and 745 torr has a volume of 37.42 L. What volume will it occupy if the pressure is increased to 894 torr at constant temperature?

Accepted Answer

A)   22.3 L
B)   31.2 L
C)   44.9 L
D)   112 L
E)   380 L

Question 15

Which gas has molecules with the greatest average molecular speed at 25°C?

Accepted Answer

A)   CH4
B)   Kr
C)   N2
D)   CO2
E)   Ar

Question 16

What is the molar mass of an unknown gas if a sample weighing 0.389 g is collected in a flask with a volume of 102 cm3 at 97°C and at a pressure of 728 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg).

Accepted Answer

A)   187 g/mol
B)   121 g/mol
C)   112 g/mol
D)   31.6 g/mol
E)   8.28 × 10-3 g/mol

Question 17

_______ ________ is theoretically the lowest attainable temperature.

Accepted Answer

The answer of _______ ________ is theoretically the lowest attainable...

Question 18

What is the pressure in atmospheres exerted by a column of water that is 12.5 m high? (density of water = 1.00g/cm3; gravitational constant = 9.80665 m/s2, 1 atm = 101,325 Pa = 760 torr = 760 mmHg)

Accepted Answer

A)   123 atm
B)   1.23 × 105 atm
C)   0.785 atm
D)   1.21 atm
E)   1.23 × 10-3 atm

Question 19

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)   739 m/s

Question 20

What is the formula which describes the relationship between the volume and temperature at constant pressure and constant number of moles?

Accepted Answer

A)   VT = k2
B)   V2/T = k2
C)   V = k2T
D)   k2VT = 0
E)   V = -k2T

Exam 10: Gases

A 3.0-L sample of helium was placed in container fitted with a porous membrane. Half of the helium effused through the membrane in 24 hours. A 3.0-L sample of oxygen was placed in an identical container. How many hours will it take for half of the oxygen to effuse through the membrane?

What is the density of Ar(g) at -11°C and 675 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

If the atmospheric pressure in Denver is 0.8800 atm, what is this pressure expressed in mmHg? (1 atm = 101,325 Pa = 760 torr, 1 torr = 1 mmHg) ?

Deviations from the ideal gas law are greater at

A sample of N₂ gas occupies 2.40 L at 20°C. At what temperature will the N₂ gas occupy a volume of 4.80 L at constant pressure?

Freon-12, CF₂Cl₂, which has been widely used in air conditioning systems, is considered a threat to the ozone layer in the stratosphere. Calculate the root-mean-square velocity of Freon-12 molecules in the lower stratosphere where the temperature is -65°C.

What are the units of the constant a in the van der Waals equation?

A 250.0-mL sample of ammonia, NH₃(g) , exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

Explain why you do not feel atmospheric pressure pushing on your body.

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

What is the temperature in Celsius at 4 K, which is the normal boiling point of liquid helium?

A flask containing argon gas is connected to a 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?

Nitrogen will behave most like an ideal gas

A sample of nitrogen gas at 298 K and 745 torr has a volume of 37.42 L. What volume will it occupy if the pressure is increased to 894 torr at constant temperature?

Which gas has molecules with the greatest average molecular speed at 25°C?

What is the molar mass of an unknown gas if a sample weighing 0.389 g is collected in a flask with a volume of 102 cm³ at 97°C and at a pressure of 728 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg) .

_ __ is theoretically the lowest attainable temperature.

What is the pressure in atmospheres exerted by a column of water that is 12.5 m high? (density of water = 1.00g/cm³; gravitational constant = 9.80665 m/s², 1 atm = 101,325 Pa = 760 torr = 760 mmHg)

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

What is the formula which describes the relationship between the volume and temperature at constant pressure and constant number of moles?

Exam 10: Gases

A 3.0-L sample of helium was placed in container fitted with a porous membrane. Half of the helium effused through the membrane in 24 hours. A 3.0-L sample of oxygen was placed in an identical container. How many hours will it take for half of the oxygen to effuse through the membrane?

What is the density of Ar(g) at -11°C and 675 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

If the atmospheric pressure in Denver is 0.8800 atm, what is this pressure expressed in mmHg? (1 atm = 101,325 Pa = 760 torr, 1 torr = 1 mmHg) ?

Deviations from the ideal gas law are greater at

A sample of N2 gas occupies 2.40 L at 20°C. At what temperature will the N2 gas occupy a volume of 4.80 L at constant pressure?

Freon-12, CF2Cl2, which has been widely used in air conditioning systems, is considered a threat to the ozone layer in the stratosphere. Calculate the root-mean-square velocity of Freon-12 molecules in the lower stratosphere where the temperature is -65°C.

What are the units of the constant a in the van der Waals equation?

A 250.0-mL sample of ammonia, NH3(g) , exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

Explain why you do not feel atmospheric pressure pushing on your body.

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

What is the temperature in Celsius at 4 K, which is the normal boiling point of liquid helium?

A flask containing argon gas is connected to a 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?

Nitrogen will behave most like an ideal gas

A sample of nitrogen gas at 298 K and 745 torr has a volume of 37.42 L. What volume will it occupy if the pressure is increased to 894 torr at constant temperature?

Which gas has molecules with the greatest average molecular speed at 25°C?

What is the molar mass of an unknown gas if a sample weighing 0.389 g is collected in a flask with a volume of 102 cm3 at 97°C and at a pressure of 728 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg) .

_______ ________ is theoretically the lowest attainable temperature.

What is the pressure in atmospheres exerted by a column of water that is 12.5 m high? (density of water = 1.00g/cm3; gravitational constant = 9.80665 m/s2, 1 atm = 101,325 Pa = 760 torr = 760 mmHg)

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

What is the formula which describes the relationship between the volume and temperature at constant pressure and constant number of moles?

A sample of N₂ gas occupies 2.40 L at 20°C. At what temperature will the N₂ gas occupy a volume of 4.80 L at constant pressure?

Freon-12, CF₂Cl₂, which has been widely used in air conditioning systems, is considered a threat to the ozone layer in the stratosphere. Calculate the root-mean-square velocity of Freon-12 molecules in the lower stratosphere where the temperature is -65°C.

A 250.0-mL sample of ammonia, NH₃(g) , exerts a pressure of 833 torr at 42.4°C. What mass of ammonia is in the container? (R = 0.08206 L • atm/K • mol, 1 atm = 760 torr)

What is the molar mass of an unknown gas if a sample weighing 0.389 g is collected in a flask with a volume of 102 cm³ at 97°C and at a pressure of 728 mmHg? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg) .

_ __ is theoretically the lowest attainable temperature.

What is the pressure in atmospheres exerted by a column of water that is 12.5 m high? (density of water = 1.00g/cm³; gravitational constant = 9.80665 m/s², 1 atm = 101,325 Pa = 760 torr = 760 mmHg)

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