Question 1

Define effusion.

Accepted Answer

Effusion is the proc...

Question 2

A 5.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure.What is the final pressure in the flask if an additional 2.00 g of N2 gas is added to the flask and the flask cooled to -55°C?

Accepted Answer

A)   0.255 atm
B)   0.987 atm
C)   1.35 atm
D)   1.84 atmE) B) and D)
F) B) and C)

Question 3

How many grams of calcium hydride are required to produce 1.14 L of hydrogen gas at 25.0°C and 0.975 atm pressure according to the chemical equation shown below? CaH2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g)

Accepted Answer

A)   0.956 g
B)   1.91 g
C)   3.82 g
D)   11.4 gE) A) and B)
F) C) and D)

Question 4

A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 629 torr.Use Charles's law to calculate the volume (L) the gas will occupy when the temperature is increased to  while maintaining the pressure at 629 torr.

Accepted Answer

A)   11.1 L
B)   13.4 L
C)   1.98 L
D)   7.47 L
E)   50.4 LF) B) and D)
G) B) and E)

Question 5

Define mean free path.

Accepted Answer

A)   average distance that a molecule travels between collisions
B)   diameter of a molecule
C)   distance between molecules in a gas
D)   time for effusion
E)   time for diffusionF) B) and C)
G) C) and D)

Question 6

What volume will 0.875 moles of Kr occupy at STP?

Accepted Answer

A)   22.4 L
B)   80.0 L
C)   43.7 atm
D)   19.6 L
E)   16.4 LF) A) and E)
G) None of the above

Question 7

Which of the following compounds will behave least like an ideal gas at low temperatures?

Accepted Answer

A)   Ar
B)   CCl4
C)   O2
D)   Kr
E)   F2F) C) and D)
G) A) and C)

Question 8

A gas occupies 22.4 L at STP and 19.0 L at 100°C and 1.50 atm pressure.How many moles of gas did the system gain or lose?

Accepted Answer

A)   0.08 moles gained
B)   0.01 moles gained
C)   0.01 moles lost
D)   0.07 moles lost
E)   1.40 moles gainedF) A) and E)
G) A) and B)

Question 9

Identify the element or molecule that has the highest effusion rate.

Accepted Answer

A)   He 
B)   O2
C)   HCl 
D)   SO2
E)   RnF) A) and C)
G) A) and D)

Question 10

Identify the temperature at which O2 has the highest velocity.

Accepted Answer

A)   325 K
B)   500 K
C)   650 K
D)   1000 K
E)   900 KF) B) and D)
G) A) and B)

Question 11

Calcium hydride ( 2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g)  How many grams of   are needed to generate 45.0 L of   gas at a pressure of 0.888 atm and a temperature of 32°C? A)  47.5 g B)  0.798 g C)  134 g D)  33.6 g E)  67.2 g" class="answers-bank-image d-inline" rel="preload" > ) reacts with water to form hydrogen gas: CaH2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g) 
How many grams of 2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g)  How many grams of   are needed to generate 45.0 L of   gas at a pressure of 0.888 atm and a temperature of 32°C? A)  47.5 g B)  0.798 g C)  134 g D)  33.6 g E)  67.2 g" class="answers-bank-image d-inline" rel="preload" > are needed to generate 45.0 L of 2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g)  How many grams of   are needed to generate 45.0 L of   gas at a pressure of 0.888 atm and a temperature of 32°C? A)  47.5 g B)  0.798 g C)  134 g D)  33.6 g E)  67.2 g" class="answers-bank-image d-inline" rel="preload" > gas at a pressure of 0.888 atm and a temperature of 32°C?

Accepted Answer

A)   47.5 g
B)   0.798 g
C)   134 g
D)   33.6 g
E)   67.2 gF) B) and E)
G) A) and B)

Question 12

A 0.334 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm.What is the identity of the halogen?

Accepted Answer

A)   Br2
B)   F2
C)   Cl2
D)   I2
E)   GeF) A) and E)
G) A) and C)

Question 13

Explain what the term "mean free path" describes.How does it change with decreasing pressure?

Accepted Answer

Mean free path describes the distance th...

Question 14

The mole fraction of krypton in dry air near sea level is 0.00000114.The concentration of krypton is ________ molecules per liter,assuming an atmospheric pressure of 739 torr and a temperature of 29.5°C.

Accepted Answer

A)   3.39 × 10-5
B)   4.46 × 10-8
C)   2.68 × 1016
D)   2.04 × 1019
E)   2.76 × 1017F) D) and E)
G) B) and E)

Question 15

A 0.500 g sample containing Ag2O and inert material is heated,causing the silver oxide to decompose according to the following equation: 2 Ag2O(s) → 4 Ag(s) + O2(g) 
If 13.8 mL of gas are collected over water at 27°C and 1.00 atm external pressure,what is the percentage of silver oxide in the sample? The partial pressure of water is 26.7 mm Hg at 27°C.

Accepted Answer

A)   12.5%
B)   25.1%
C)   50.1%
D)   51.9%E) A) and D)
F) B) and D)

Question 16

A mixture of 0.220 moles CO,0.350 moles F2 and 0.640 moles He has a total pressure of 2.95 atm.What is the partial pressure of CO?

Accepted Answer

A)   1.86 atm
B)   0.649 atm
C)   0.536 atm
D)   1.54 atm
E)   0.955 atmF) B) and C)
G) A) and B)

Question 17

How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F2(g) → XeF6(g)

Accepted Answer

A)   1.21 × 1023 molecules XeF6
B)   8.25 × 1023 molecules XeF6
C)   2.75 × 1023 molecules XeF6
D)   7.29 × 1023 molecules XeF6
E)   1.37 × 1023 molecules XeF6F) B) and D)
G) A) and D)

Question 18

The density of krypton gas at 1.35 atm and 54.1°C is ________ g/L.

Accepted Answer

A)   0.0503
B)   0.237
C)   0.304
D)   4.21
E)   8.42F) C) and E)
G) A) and C)

Question 19

A mixture of Ar,H2 and SO2 has a pressure of 7.85 atm.If the Ar has a mole fraction of 0.47 and H2 has a mole fraction of 0.23,what is the partial pressure of SO2?

Accepted Answer

A)   4.2 atm
B)   3.7 atm
C)   1.8 atm
D)   5.5 atm
E)   2.4 atmF) None of the above
G) C) and E)

Question 20

The mole fraction of oxygen in dry air near sea level is 0.20948,where the molar mass of oxygen is 31.998.The partial pressure of oxygen when the total atmospheric pressure (dry air) is 97.5 kPa is

Accepted Answer

A)   471
B)   14.7
C)   20.7
D)   661
E)   0.646F) D) and E)
G) A) and D)

Exam 5: Gases

Define effusion.

Correct Answer
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Effusion is the proc...
View Answer

A mixture of 0.220 moles CO,0.350 moles F₂ and 0.640 moles He has a total pressure of 2.95 atm.What is the partial pressure of CO?

Correct Answer
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A mixture of Ar,H₂ and SO₂ has a pressure of 7.85 atm.If the Ar has a mole fraction of 0.47 and H₂ has a mole fraction of 0.23,what is the partial pressure of SO₂?

Correct Answer
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Define mean free path.

Correct Answer
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Correct Answer
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Identify the element or molecule that has the highest effusion rate.

Correct Answer
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Identify the temperature at which O₂ has the highest velocity.

Correct Answer
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A gas occupies 22.4 L at STP and 19.0 L at 100°C and 1.50 atm pressure.How many moles of gas did the system gain or lose?

Correct Answer
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The mole fraction of krypton in dry air near sea level is 0.00000114.The concentration of krypton is ________ molecules per liter,assuming an atmospheric pressure of 739 torr and a temperature of 29.5°C.

Correct Answer
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What volume will 0.875 moles of Kr occupy at STP?

Correct Answer
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Explain what the term "mean free path" describes.How does it change with decreasing pressure?

Correct Answer
verified
Mean free path describes the distance th...
View Answer

How many grams of calcium hydride are required to produce 1.14 L of hydrogen gas at 25.0°C and 0.975 atm pressure according to the chemical equation shown below? CaH₂(s) + 2 H₂O(l) → Ca(OH) ₂(aq) + 2 H₂(g)

Correct Answer
verified

How many molecules of XeF₆are formed from 12.9 L of F₂ (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F₂(g) → XeF₆(g)

Correct Answer
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The density of krypton gas at 1.35 atm and 54.1°C is ________ g/L.

Correct Answer
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A 5.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure.What is the final pressure in the flask if an additional 2.00 g of N₂ gas is added to the flask and the flask cooled to -55°C?

Correct Answer
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A 0.334 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm.What is the identity of the halogen?

Correct Answer
verified

Calcium hydride ( ) reacts with water to form hydrogen gas: CaH₂(s) + 2 H₂O(l) → Ca(OH) ₂(aq) + 2 H₂(g) How many grams of are needed to generate 45.0 L of gas at a pressure of 0.888 atm and a temperature of 32°C?

Correct Answer
verified

Which of the following compounds will behave least like an ideal gas at low temperatures?

Correct Answer
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Correct Answer
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A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 629 torr.Use Charles's law to calculate the volume (L) the gas will occupy when the temperature is increased to while maintaining the pressure at 629 torr.

Correct Answer
verified

Exam 5: Gases

Define effusion.

Correct AnswerverifiedEffusion is the proc...View AnswerShow Answer

A mixture of 0.220 moles CO,0.350 moles F2 and 0.640 moles He has a total pressure of 2.95 atm.What is the partial pressure of CO?

Correct AnswerverifiedShow Answer

A mixture of Ar,H2 and SO2 has a pressure of 7.85 atm.If the Ar has a mole fraction of 0.47 and H2 has a mole fraction of 0.23,what is the partial pressure of SO2?

Correct AnswerverifiedShow Answer

Define mean free path.

Correct AnswerverifiedShow Answer

The mole fraction of oxygen in dry air near sea level is 0.20948,where the molar mass of oxygen is 31.998.The partial pressure of oxygen when the total atmospheric pressure (dry air) is 97.5 kPa is

Correct AnswerverifiedShow Answer

Identify the element or molecule that has the highest effusion rate.

Correct AnswerverifiedShow Answer

Identify the temperature at which O2 has the highest velocity.

Correct AnswerverifiedShow Answer

A gas occupies 22.4 L at STP and 19.0 L at 100°C and 1.50 atm pressure.How many moles of gas did the system gain or lose?

Correct AnswerverifiedShow Answer

The mole fraction of krypton in dry air near sea level is 0.00000114.The concentration of krypton is ________ molecules per liter,assuming an atmospheric pressure of 739 torr and a temperature of 29.5°C.

Correct AnswerverifiedShow Answer

What volume will 0.875 moles of Kr occupy at STP?

Correct AnswerverifiedShow Answer

Explain what the term "mean free path" describes.How does it change with decreasing pressure?

Correct AnswerverifiedMean free path describes the distance th...View AnswerShow Answer

How many grams of calcium hydride are required to produce 1.14 L of hydrogen gas at 25.0°C and 0.975 atm pressure according to the chemical equation shown below? CaH2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g)

Correct AnswerverifiedShow Answer

How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F2(g) → XeF6(g)

Correct AnswerverifiedShow Answer

The density of krypton gas at 1.35 atm and 54.1°C is ________ g/L.

Correct AnswerverifiedShow Answer

A 5.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure.What is the final pressure in the flask if an additional 2.00 g of N2 gas is added to the flask and the flask cooled to -55°C?

Correct AnswerverifiedShow Answer

A 0.334 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm.What is the identity of the halogen?

Correct AnswerverifiedShow Answer

Calcium hydride ( ) reacts with water to form hydrogen gas: CaH2(s) + 2 H2O(l) → Ca(OH) 2(aq) + 2 H2(g) How many grams of are needed to generate 45.0 L of gas at a pressure of 0.888 atm and a temperature of 32°C?

Correct AnswerverifiedShow Answer

Which of the following compounds will behave least like an ideal gas at low temperatures?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 629 torr.Use Charles's law to calculate the volume (L) the gas will occupy when the temperature is increased to while maintaining the pressure at 629 torr.

Correct AnswerverifiedShow Answer

Correct Answer
verified
Effusion is the proc...
View Answer

A mixture of 0.220 moles CO,0.350 moles F₂ and 0.640 moles He has a total pressure of 2.95 atm.What is the partial pressure of CO?

Correct Answer
verified

A mixture of Ar,H₂ and SO₂ has a pressure of 7.85 atm.If the Ar has a mole fraction of 0.47 and H₂ has a mole fraction of 0.23,what is the partial pressure of SO₂?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Identify the temperature at which O₂ has the highest velocity.

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
verified
Mean free path describes the distance th...
View Answer

How many grams of calcium hydride are required to produce 1.14 L of hydrogen gas at 25.0°C and 0.975 atm pressure according to the chemical equation shown below? CaH₂(s) + 2 H₂O(l) → Ca(OH) ₂(aq) + 2 H₂(g)

Correct Answer
verified

How many molecules of XeF₆are formed from 12.9 L of F₂ (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F₂(g) → XeF₆(g)

Correct Answer
verified

Correct Answer
verified

A 5.00-L flask contains nitrogen gas at 25°C and 1.00 atm pressure.What is the final pressure in the flask if an additional 2.00 g of N₂ gas is added to the flask and the flask cooled to -55°C?

Correct Answer
verified

Correct Answer
verified

Calcium hydride ( ) reacts with water to form hydrogen gas: CaH₂(s) + 2 H₂O(l) → Ca(OH) ₂(aq) + 2 H₂(g) How many grams of are needed to generate 45.0 L of gas at a pressure of 0.888 atm and a temperature of 32°C?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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