Question 1

A spacecraft is filled with 0.500 atm of O2 and 0.500 atm of He. If there is a very small hole in the side of this craft such that gas is lost slowly into outer space,

Accepted Answer

A)  He is lost 2.8 times faster than O2 is lost.
B)  He is lost 8 times faster than O2 is lost.
C)  He is lost twice as fast as O2 is lost.
D)  O2 is lost 2.8 times faster than He is lost.
E)  O2 is lost 8 times faster than He is lost.F) B) and E)
G) A) and B)

Question 2

Calculate the number of moles of gas contained in a 10.0 L tank at 22°C and 105 atm.(R = 0.08206 L.atm/K.mol)

Accepted Answer

A)  1.71 * 10-3 mol
B)  0.0231 mol
C)  1.03 mol
D)  43.4 mol
E)  582 molF) A) and B)
G) C) and D)

Question 3

The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at 1.00 atm and 25°C is required for burning 1.00 L of hexane (C6H14, density = 0.660 g/mL) completely, yielding carbon dioxide and water?

Accepted Answer

A)  187 L
B)  712 L
C)  1780 L
D)  894 L
E)  8490F) A) and D)
G) D) and E)

Question 4

How many molecules of N2 gas can be present in a 2.5 L flask at 50°C and 650 mmHg?

Accepted Answer

A)  2.1 * 10-23 molecules
B)  4.9 * 1022 molecules
C)  3.1 * 1023 molecules
D)  3.6 * 1025 molecules
E)  0.081 moleculesF) A) and C)
G) A) and E)

Question 5

Calculate the density, in g/L, of chlorine (Cl2) gas at STP.

Accepted Answer

A)  2.13 * 10-2 g/L
B)  46.9 g/L
C)  1.58 g/L
D)  3.16 g/L
E)  0.316 kg/LF) A) and D)
G) All of the above

Question 6

The pressure of a gas sample was measured to be 489 mmHg.Which of the following is not an equivalent statement of that pressure? (1 atm = 1.01325 * 105 Pa)

Accepted Answer

A)  65.2 kPa
B)  6.52 * 104 Pa
C)  489 torr
D)  0.811 atmE) None of the above
F) A) and B)

Question 7

What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 736 mmHg and h = 9.2 cm?

Accepted Answer

A)  92 mmHg
B)  644 mmHg
C)  736 mmHg
D)  828 mmHgE) A) and B)
F) A) and C)

Question 8

Samples of the following volatile liquids are opened simultaneously at one end of a room. If you are standing at the opposite end of this room, which species would you smell first? (Assume that your nose is equally sensitive to all these species.)

Accepted Answer

A)  ethyl acetate (CH3COOC2H5) 
B)  camphor (C10H16O) 
C)  diethyl ether (C2H5OC2H5) 
D)  naphthalene (C10H8) 
E)  pentanethiol (C5H11SH) F) B) and C)
G) A) and E)

Question 9

At constant pressure, the density of a gas depends on temperature.Does the density increase or decrease as the temperature increases?

Accepted Answer

The answer of At constant pressure, the density of a...

Question 10

What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 742 mmHg and h = 16.7 cm?

Accepted Answer

The answer of What is the pressure of the sample...

Question 11

Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres, will be exerted by 2,500 g of oxygen gas (O2) when stored at 22°C in a 40.0 L cylinder?

Accepted Answer

A)  3.55 atm
B)  1,510 atm
C)  47.3 atm
D)  7.56 * 104 atm
E)  10.2 atmF) C) and D)
G) B) and D)

Question 12

Ammonium nitrite undergoes decomposition to produce only gases as shown below.
NH4NO2(s)$\rarr$ N2(g)+ 2H2O(g)
How many liters of gas will be produced by the decomposition of 32.0 g of NH4NO2 at 525°C and 1.5 atm?

Accepted Answer

The answer of Ammonium nitrite undergoes decomposition to produce only...

Question 13

Determine the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 695 mmHg.

Accepted Answer

A)  45 mmHg
B)  650 mmHg
C)  695 mmHg
D)  740 mmHg
E)  760 mmHgF) A) and D)
G) A) and C)

Question 14

A 0.271 g sample of an unknown vapor occupies 294 mL at 140°C and 847 mmHg.The empirical formula of the compound is CH2. What is the molecular formula of the compound?

Accepted Answer

A)  CH2
B)  C2H4
C)  C3H6
D)  C4H8
E)  C6H12F) A) and D)
G) A) and B)

Question 15

Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100.cm3 at 95°C, and 1,000.mmHg.

Accepted Answer

A)  0.19 g/mol
B)  35.3 g/mol
C)  70.9 g/mol
D)  137 g/mol
E)  384 g/molF) B) and D)
G) All of the above

Question 16

A sample of hydrogen gas was collected over water at 21°C and 685 mmHg. The volume of the container was 7.80 L. Calculate the mass of H2(g) collected. (Vapor pressure of water = 18.6 mmHg at 21°C.)

Accepted Answer

A)  0.283 g
B)  0.572 g
C)  0.589 g
D)  7.14 g
E)  435 gF) A) and E)
G) B) and E)

Question 17

At what temperature will a fixed mass of gas with a volume of 125 L at 15°C and 750 mmHg occupy a volume of 101 L at a pressure of 645 mm Hg?

Accepted Answer

A)  -73°C
B)  10.4°C
C)  2°C
D)  34°C
E)  200°CF) B) and C)
G) C) and D)

Question 18

What will happen to the height (h) of the mercury column in the manometer shown below if the stopcock is opened, given that the atmospheric pressure is 755 mmHg?

Accepted Answer

A)  h will decrease
B)  h will not change
C)  h will increase
D)  not enough information given to answer the questionE) None of the above
F) B) and D)

Question 19

The gas pressure in an aerosol can is 1.8 atm at 25°C. If the gas is an ideal gas, what pressure would develop in the can if it were heated to 475°C?

Accepted Answer

A)  0.095 atm
B)  0.717 atm
C)  3.26 atm
D)  4.52 atm
E)  34.2 atmF) B) and D)
G) B) and C)

Question 20

A particular coal sample contains 2.32% S.When the coal is burned, the sulfur is converted to sulfur dioxide gas. What volume of SO2(g), measured at 25°C and 749 mmHg, is produced by burning 2.0 * 106 lb of this coal? (1 lb = 454 g)

Accepted Answer

1.6 * 10<s...

Exam 5: Gases

Samples of the following volatile liquids are opened simultaneously at one end of a room. If you are standing at the opposite end of this room, which species would you smell first? (Assume that your nose is equally sensitive to all these species.)

Correct AnswerverifiedShow Answer

Calculate the number of moles of gas contained in a 10.0 L tank at 22°C and 105 atm.(R = 0.08206 L.atm/K.mol)

Correct AnswerverifiedShow Answer

A sample of hydrogen gas was collected over water at 21°C and 685 mmHg. The volume of the container was 7.80 L. Calculate the mass of H2(g) collected. (Vapor pressure of water = 18.6 mmHg at 21°C.)

Correct AnswerverifiedShow Answer

How many molecules of N2 gas can be present in a 2.5 L flask at 50°C and 650 mmHg?

Correct AnswerverifiedShow Answer

At constant pressure, the density of a gas depends on temperature.Does the density increase or decrease as the temperature increases?

Correct AnswerverifiedShow Answer

Determine the pressure of the gas trapped in the apparatus shown below when the atmospheric pressure is 695 mmHg.

Correct AnswerverifiedShow Answer

The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at 1.00 atm and 25°C is required for burning 1.00 L of hexane (C6H14, density = 0.660 g/mL) completely, yielding carbon dioxide and water?

Correct AnswerverifiedShow Answer

What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 742 mmHg and h = 16.7 cm?

Correct AnswerverifiedShow Answer

A 0.271 g sample of an unknown vapor occupies 294 mL at 140°C and 847 mmHg.The empirical formula of the compound is CH2. What is the molecular formula of the compound?

Correct AnswerverifiedShow Answer

A spacecraft is filled with 0.500 atm of O2 and 0.500 atm of He. If there is a very small hole in the side of this craft such that gas is lost slowly into outer space,

Correct AnswerverifiedShow Answer

Calculate the density, in g/L, of chlorine (Cl2) gas at STP.

Correct AnswerverifiedShow Answer

Ammonium nitrite undergoes decomposition to produce only gases as shown below. NH4NO2(s) →\rarr→ N2(g)+ 2H2O(g) How many liters of gas will be produced by the decomposition of 32.0 g of NH4NO2 at 525°C and 1.5 atm?

Correct AnswerverifiedShow Answer

What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown below if atmospheric pressure is 736 mmHg and h = 9.2 cm?

Correct AnswerverifiedShow Answer

Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100.cm3 at 95°C, and 1,000.mmHg.

Correct AnswerverifiedShow Answer

At what temperature will a fixed mass of gas with a volume of 125 L at 15°C and 750 mmHg occupy a volume of 101 L at a pressure of 645 mm Hg?

Correct AnswerverifiedShow Answer

What will happen to the height (h) of the mercury column in the manometer shown below if the stopcock is opened, given that the atmospheric pressure is 755 mmHg?

Correct AnswerverifiedShow Answer

Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres, will be exerted by 2,500 g of oxygen gas (O2) when stored at 22°C in a 40.0 L cylinder?

Correct AnswerverifiedShow Answer

A particular coal sample contains 2.32% S.When the coal is burned, the sulfur is converted to sulfur dioxide gas. What volume of SO2(g), measured at 25°C and 749 mmHg, is produced by burning 2.0 * 106 lb of this coal? (1 lb = 454 g)

Correct Answerverified1.6 * 10View AnswerShow Answer

The gas pressure in an aerosol can is 1.8 atm at 25°C. If the gas is an ideal gas, what pressure would develop in the can if it were heated to 475°C?

Correct AnswerverifiedShow Answer

The pressure of a gas sample was measured to be 489 mmHg.Which of the following is not an equivalent statement of that pressure? (1 atm = 1.01325 * 105 Pa)

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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A sample of hydrogen gas was collected over water at 21°C and 685 mmHg. The volume of the container was 7.80 L. Calculate the mass of H₂(g) collected. (Vapor pressure of water = 18.6 mmHg at 21°C.)

Correct Answer
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How many molecules of N₂ gas can be present in a 2.5 L flask at 50°C and 650 mmHg?

Correct Answer
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Correct Answer
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Correct Answer
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The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at 1.00 atm and 25°C is required for burning 1.00 L of hexane (C₆H₁₄, density = 0.660 g/mL) completely, yielding carbon dioxide and water?

Correct Answer
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Correct Answer
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A 0.271 g sample of an unknown vapor occupies 294 mL at 140°C and 847 mmHg.The empirical formula of the compound is CH₂. What is the molecular formula of the compound?

Correct Answer
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A spacecraft is filled with 0.500 atm of O₂ and 0.500 atm of He. If there is a very small hole in the side of this craft such that gas is lost slowly into outer space,

Correct Answer
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Calculate the density, in g/L, of chlorine (Cl₂) gas at STP.

Correct Answer
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Ammonium nitrite undergoes decomposition to produce only gases as shown below. NH₄NO₂(s) $\rarr$ N₂(g)+ 2H₂O(g) How many liters of gas will be produced by the decomposition of 32.0 g of NH₄NO₂ at 525°C and 1.5 atm?

Correct Answer
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Correct Answer
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Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100.cm³ at 95°C, and 1,000.mmHg.

Correct Answer
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Correct Answer
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Correct Answer
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Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres, will be exerted by 2,500 g of oxygen gas (O₂) when stored at 22°C in a 40.0 L cylinder?

Correct Answer
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A particular coal sample contains 2.32% S.When the coal is burned, the sulfur is converted to sulfur dioxide gas. What volume of SO₂(g), measured at 25°C and 749 mmHg, is produced by burning 2.0 * 10⁶ lb of this coal? (1 lb = 454 g)

Correct Answer
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1.6 * 10
View Answer

Correct Answer
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The pressure of a gas sample was measured to be 489 mmHg.Which of the following is not an equivalent statement of that pressure? (1 atm = 1.01325 * 10⁵ Pa)

Correct Answer
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