Question 1

The molar masses of helium and oxygen are 4.0 g/mol and 16 g/mol,respectively.At the same temperature and pressure,1 mole of helium will occupy

Accepted Answer

A)   the same volume as 1 mole of oxygen.
B)   four times the volume of 1 mole of oxygen.
C)   twice the volume of 1 mole of oxygen.
D)   half the volume of 1 mole of oxygen.
E)   one-fourth the volume of 1 mole of oxygen.

Question 2

A sample of carbon dioxide is collected over water at 25°C (vapor pressure H2O(l) = 23.8 mm Hg) .The CO2 and water vapor occupy a volume of 1.80 L at a pressure of 783.0 mm Hg.What mass of CO2 is present?

Accepted Answer

A)   3.23 g
B)   4.40 g
C)   9.02 g
D)   14.7 g
E)   16.3 g

Question 3

If the volume of a confined gas is expanded to four times the original volume while its temperature remains constant,what change will be observed?

Accepted Answer

A)   The pressure of the gas will decrease to 1/4 of its original value.
B)   The pressure of the gas will decrease to 1/2 of its original value.
C)   The pressure of the gas will remain unchanged.
D)   The pressure of the gas will increase to twice its original value.
E)   The pressure of the gas will increase to four times its original value.

Question 4

What volume does 22.4 moles of hydrogen gas occupy at 0°C and 1.00 atm?

Accepted Answer

A)   0.0821 L
B)   1.00 L
C)   22.4 L
D)   184 L
E)   502 L

Question 5

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.If 2.33 g of water is decomposed to H2(g) and O2(g) and the gases are collected in a 1.00 L flask over water at 25°C (vapor pressure H2O(l) = 23.8 mm Hg) ,what is the pressure in the flask?

Accepted Answer

A)   3.19 atm
B)   4.71 atm
C)   4.75 atm
D)   4.78 atm
E)   9.52 atm

Question 6

Methane gas,CH4,effuses through a barrier at a rate of 0.568 mL/minute.If an unknown gas effuses through the same barrier at a rate of 0.343 mL/minute,what is the molar mass of the gas?

Accepted Answer

A)   20.8 g/mol
B)   28.0 g/mol
C)   32.0 g/mol
D)   43.9 g/mol
E)   64.0 g/mol

Question 7

A balloon is filled with He gas to a volume of 2.10 L at 35°C.The balloon is placed in liquid nitrogen until its temperature reaches -196°C.Assuming the pressure remains constant,what is the volume of the cooled balloon?

Accepted Answer

A)   −0.375 L
B)   0.375 L
C)   0.525 L
D)   0.00909 L
E)   8.40 L

Question 8

At 338 mm Hg and 72°C,a sample of carbon monoxide gas occupies a volume of 0.225 L.The gas is transferred to a 1.50-L flask and the temperature is reduced to -15°C.What is the pressure of the gas in the flask?

Accepted Answer

A)   8.91 mm Hg
B)   37.9 mm Hg
C)   67.8 mm Hg
D)   3.018 × 103 mm Hg
E)   5.48 × 104 mm Hg

Question 9

An unknown gas contains 85.6% C and 14.4% H.At 0.455 atm and 425 K,the gas has a density of 0.549 g/L.What is the molecular formula of the gas?

Accepted Answer

A)   CH4
B)   C2H4
C)   C3H6
D)   C4H6
E)   C4H8

Question 10

In an experiment,argon is allowed to effuse through a tiny opening into an evacuated 5.00 × 102 mL flask for 30.0 seconds,at which point the pressure in the flask is found to be 15.0 mm Hg.The experiment is repeated using an unknown gas at the same temperature and pressure.After 30.0 seconds,the pressure is found to be 47.4 mm Hg.What is the molar mass of the gas?

Accepted Answer

A)   4.00 g/mol
B)   16.0 g/mol
C)   28.0 g/mol
D)   32.0 g/mol
E)   83.8 g/mol A

Question 11

A volatile compound with a mass of 0.8822 grams is placed in an evacuated 0.250 L flask.The flask is heated to evaporate the compound.At 99°C,the pressure in the flask is 1.25 atm.What is the molar mass of the compound?

Accepted Answer

A)   86.2 g/mol
B)   116 g/mol
C)   229 g/mol
D)   257 g/mol
E)   303 g/mol

Question 12

At 1.00 km above sea level,the atmospheric pressure is 675 mm Hg and the temperature is 282 K.If nitrogen comprises 78.1% (mole percent) of air,what is the density of nitrogen at this height?

Accepted Answer

A)   0.0238 g/L
B)   0.521 g/L
C)   0.839 g/L
D)   1.07 g/L
E)   638 g/L

Question 13

Calculate the density (in g/L) of CH4(g) at 75°C and 2.1 atm.(R = 0.08206 L · atm/mol · K)

Accepted Answer

A)   0.18 g/L
B)   0.85 g/L
C)   1.2 g/L
D)   3.2 g/L
E)   5.5 g/L

Question 14

At 21°C,a gas cylinder containing nitrogen has an internal volume and pressure of 46.6 L and 1.50 × 102 atm.What mass of nitrogen gas is contained in the cylinder?

Accepted Answer

A)   2.90 × 102 g
B)   4.05 × 103 g
C)   8.11 × 103 g
D)   1.14 × 105 g
E)   none of the above

Question 15

A balloon is filled with 1.50 L of helium gas at sea level,1.00 atm and 32°C.The balloon is released and it rises to an altitude of 30,000 ft.If the pressure at this altitude is 228 mm Hg and the temperature is −45°C,what is the volume of the balloon?

Accepted Answer

A)   0.336 L
B)   1.56 L
C)   1.68 L
D)   2.81 L
E)   3.74 L

Question 16

Place the following units of pressure in order from lowest to highest pressure.

Accepted Answer

A)   1 atm 
B)   1 mm Hg 
C)   1 Pa 
D)   1 Pa 
E)   1 bar < 1 mm Hg < 1 Pa < 1 atm

Question 17

A tightly sealed 4.0-L flask contains 884 mm Hg of N2 at 94.0°C.The flask is cooled until the pressure is reduced to 442 mm Hg.What is the temperature of the gas?

Accepted Answer

A)   -47.0°C
B)   47.0°C
C)   -89.5°C
D)   184°C
E)   188°C C

Question 18

A volume of 3.0 L of butane is burned in excess oxygen.Balance the chemical equation below and determine how many total liters of gases are produced.Assume that both the reactant and product temperature is 500 K and the pressure of the system remains constant at 1.0 atm. 
C4H10(g) + O2(g) → CO2(g) + H2O(g)

Accepted Answer

A)   3.0 L
B)   6.0 L
C)   12 L
D)   27 L
E)   42 L

Question 19

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.What mass of water must decompose to yield 24.0 L of oxygen gas at 1.00 atm and 25°C? 
2H2O(l) → 2H2(g) + O2(g)

Accepted Answer

A)   11.1 g
B)   17.7 g
C)   23.6 g
D)   35.3 g
E)   70.7 g

Question 20

Avogadro's law states that

Accepted Answer

A)   1 liter of any gas contains 6.02 × 1023 gas molecules.
B)   the volume of a gas is directly proportional to its temperature.
C)   the gas constant equals 0.0821 L · atm/(mol · K) for all ideal gases.
D)   the volume of a gas must always be a constant.
E)   equal volumes of all gases at the same pressure and temperature contain an equal number of moles. E

Exam 5: Gases

The molar masses of helium and oxygen are 4.0 g/mol and 16 g/mol,respectively.At the same temperature and pressure,1 mole of helium will occupy

Correct Answer
verified

A sample of carbon dioxide is collected over water at 25°C (vapor pressure H₂O(l) = 23.8 mm Hg) .The CO₂ and water vapor occupy a volume of 1.80 L at a pressure of 783.0 mm Hg.What mass of CO₂ is present?

Correct Answer
verified

If the volume of a confined gas is expanded to four times the original volume while its temperature remains constant,what change will be observed?

Correct Answer
verified

What volume does 22.4 moles of hydrogen gas occupy at 0°C and 1.00 atm?

Correct Answer
verified

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.If 2.33 g of water is decomposed to H₂(g) and O₂(g) and the gases are collected in a 1.00 L flask over water at 25°C (vapor pressure H₂O(l) = 23.8 mm Hg) ,what is the pressure in the flask?

Correct Answer
verified

Methane gas,CH₄,effuses through a barrier at a rate of 0.568 mL/minute.If an unknown gas effuses through the same barrier at a rate of 0.343 mL/minute,what is the molar mass of the gas?

Correct Answer
verified

A balloon is filled with He gas to a volume of 2.10 L at 35°C.The balloon is placed in liquid nitrogen until its temperature reaches -196°C.Assuming the pressure remains constant,what is the volume of the cooled balloon?

Correct Answer
verified

At 338 mm Hg and 72°C,a sample of carbon monoxide gas occupies a volume of 0.225 L.The gas is transferred to a 1.50-L flask and the temperature is reduced to -15°C.What is the pressure of the gas in the flask?

Correct Answer
verified

An unknown gas contains 85.6% C and 14.4% H.At 0.455 atm and 425 K,the gas has a density of 0.549 g/L.What is the molecular formula of the gas?

Correct Answer
verified

Correct Answer
verified
A

A volatile compound with a mass of 0.8822 grams is placed in an evacuated 0.250 L flask.The flask is heated to evaporate the compound.At 99°C,the pressure in the flask is 1.25 atm.What is the molar mass of the compound?

Correct Answer
verified

At 1.00 km above sea level,the atmospheric pressure is 675 mm Hg and the temperature is 282 K.If nitrogen comprises 78.1% (mole percent) of air,what is the density of nitrogen at this height?

Correct Answer
verified

Calculate the density (in g/L) of CH₄(g) at 75°C and 2.1 atm.(R = 0.08206 L · atm/mol · K)

Correct Answer
verified

At 21°C,a gas cylinder containing nitrogen has an internal volume and pressure of 46.6 L and 1.50 × 10² atm.What mass of nitrogen gas is contained in the cylinder?

Correct Answer
verified

A balloon is filled with 1.50 L of helium gas at sea level,1.00 atm and 32°C.The balloon is released and it rises to an altitude of 30,000 ft.If the pressure at this altitude is 228 mm Hg and the temperature is −45°C,what is the volume of the balloon?

Correct Answer
verified

Place the following units of pressure in order from lowest to highest pressure.

Correct Answer
verified

A tightly sealed 4.0-L flask contains 884 mm Hg of N₂ at 94.0°C.The flask is cooled until the pressure is reduced to 442 mm Hg.What is the temperature of the gas?

Correct Answer
verified
C

Correct Answer
verified

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.What mass of water must decompose to yield 24.0 L of oxygen gas at 1.00 atm and 25°C? 2H₂O(l) → 2H₂(g) + O₂(g)

Correct Answer
verified

Avogadro's law states that

Correct Answer
verified
E

Exam 5: Gases

The molar masses of helium and oxygen are 4.0 g/mol and 16 g/mol,respectively.At the same temperature and pressure,1 mole of helium will occupy

Correct AnswerverifiedShow Answer

A sample of carbon dioxide is collected over water at 25°C (vapor pressure H2O(l) = 23.8 mm Hg) .The CO2 and water vapor occupy a volume of 1.80 L at a pressure of 783.0 mm Hg.What mass of CO2 is present?

Correct AnswerverifiedShow Answer

If the volume of a confined gas is expanded to four times the original volume while its temperature remains constant,what change will be observed?

Correct AnswerverifiedShow Answer

What volume does 22.4 moles of hydrogen gas occupy at 0°C and 1.00 atm?

Correct AnswerverifiedShow Answer

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.If 2.33 g of water is decomposed to H2(g) and O2(g) and the gases are collected in a 1.00 L flask over water at 25°C (vapor pressure H2O(l) = 23.8 mm Hg) ,what is the pressure in the flask?

Correct AnswerverifiedShow Answer

Methane gas,CH4,effuses through a barrier at a rate of 0.568 mL/minute.If an unknown gas effuses through the same barrier at a rate of 0.343 mL/minute,what is the molar mass of the gas?

Correct AnswerverifiedShow Answer

A balloon is filled with He gas to a volume of 2.10 L at 35°C.The balloon is placed in liquid nitrogen until its temperature reaches -196°C.Assuming the pressure remains constant,what is the volume of the cooled balloon?

Correct AnswerverifiedShow Answer

At 338 mm Hg and 72°C,a sample of carbon monoxide gas occupies a volume of 0.225 L.The gas is transferred to a 1.50-L flask and the temperature is reduced to -15°C.What is the pressure of the gas in the flask?

Correct AnswerverifiedShow Answer

An unknown gas contains 85.6% C and 14.4% H.At 0.455 atm and 425 K,the gas has a density of 0.549 g/L.What is the molecular formula of the gas?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

A volatile compound with a mass of 0.8822 grams is placed in an evacuated 0.250 L flask.The flask is heated to evaporate the compound.At 99°C,the pressure in the flask is 1.25 atm.What is the molar mass of the compound?

Correct AnswerverifiedShow Answer

At 1.00 km above sea level,the atmospheric pressure is 675 mm Hg and the temperature is 282 K.If nitrogen comprises 78.1% (mole percent) of air,what is the density of nitrogen at this height?

Correct AnswerverifiedShow Answer

Calculate the density (in g/L) of CH4(g) at 75°C and 2.1 atm.(R = 0.08206 L · atm/mol · K)

Correct AnswerverifiedShow Answer

At 21°C,a gas cylinder containing nitrogen has an internal volume and pressure of 46.6 L and 1.50 × 102 atm.What mass of nitrogen gas is contained in the cylinder?

Correct AnswerverifiedShow Answer

A balloon is filled with 1.50 L of helium gas at sea level,1.00 atm and 32°C.The balloon is released and it rises to an altitude of 30,000 ft.If the pressure at this altitude is 228 mm Hg and the temperature is −45°C,what is the volume of the balloon?

Correct AnswerverifiedShow Answer

Place the following units of pressure in order from lowest to highest pressure.

Correct AnswerverifiedShow Answer

A tightly sealed 4.0-L flask contains 884 mm Hg of N2 at 94.0°C.The flask is cooled until the pressure is reduced to 442 mm Hg.What is the temperature of the gas?

Correct AnswerverifiedC

Correct AnswerverifiedShow Answer

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.What mass of water must decompose to yield 24.0 L of oxygen gas at 1.00 atm and 25°C? 2H2O(l) → 2H2(g) + O2(g)

Correct AnswerverifiedShow Answer

Avogadro's law states that

Correct AnswerverifiedE

Correct Answer
verified

A sample of carbon dioxide is collected over water at 25°C (vapor pressure H₂O(l) = 23.8 mm Hg) .The CO₂ and water vapor occupy a volume of 1.80 L at a pressure of 783.0 mm Hg.What mass of CO₂ is present?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.If 2.33 g of water is decomposed to H₂(g) and O₂(g) and the gases are collected in a 1.00 L flask over water at 25°C (vapor pressure H₂O(l) = 23.8 mm Hg) ,what is the pressure in the flask?

Correct Answer
verified

Methane gas,CH₄,effuses through a barrier at a rate of 0.568 mL/minute.If an unknown gas effuses through the same barrier at a rate of 0.343 mL/minute,what is the molar mass of the gas?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

Calculate the density (in g/L) of CH₄(g) at 75°C and 2.1 atm.(R = 0.08206 L · atm/mol · K)

Correct Answer
verified

At 21°C,a gas cylinder containing nitrogen has an internal volume and pressure of 46.6 L and 1.50 × 10² atm.What mass of nitrogen gas is contained in the cylinder?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A tightly sealed 4.0-L flask contains 884 mm Hg of N₂ at 94.0°C.The flask is cooled until the pressure is reduced to 442 mm Hg.What is the temperature of the gas?

Correct Answer
verified
C

Correct Answer
verified

Water can be decomposed by electrolysis to hydrogen gas and oxygen gas.What mass of water must decompose to yield 24.0 L of oxygen gas at 1.00 atm and 25°C? 2H₂O(l) → 2H₂(g) + O₂(g)

Correct Answer
verified

Correct Answer
verified
E