Question 1

How many molecules of He are contained in a 10.0 L tank at 7.53 atm and 485 K?

Accepted Answer

A)  1.89 × 1024 molecules 
B)  1.14 × 1024 molecules 
C)  8.32 × 1024 molecules 
D)  4.89 × 1024 molecules 
E)  3.63 × 1024 molecules 
A)  1.89 × 1024 molecules 
B)  1.14 × 1024 molecules 
C)  8.32 × 1024 molecules 
D)  4.89 × 1024 molecules 
E)  3.63 × 1024 molecules

Question 2

Define hypoxia.

Accepted Answer

A)  oxygen starvation 
B)  increased oxygen concentration in body tissues 
C)  increased nitrogen concentration in body tissues and fluids 
D)  nitrogen starvation 
A)  oxygen starvation 
B)  increased oxygen concentration in body tissues 
C)  increased nitrogen concentration in body tissues and fluids 
D)  nitrogen starvation

Question 3

How many liters of oxygen are needed to react with 2.878 g of octane at STP?
2C8H18(g)+ 25O2(g)→ 16CO2(g)+18H2O(g)

Accepted Answer

A)  8.21 L 
B)  7.04 L 
C)  6.72 L 
D)  7.68 L 
A)  8.21 L 
B)  7.04 L 
C)  6.72 L 
D)  7.68 L

Question 4

If a sample of 0.29 moles of Ar occupies 3.8 L under certain conditions,what volume will 0.66 moles occupy under the same conditions?

Accepted Answer

A)  12 L 
B)  8.6 L 
C)  17 L 
D)  5.0 L 
E)  15 L 
A)  12 L 
B)  8.6 L 
C)  17 L 
D)  5.0 L 
E)  15 L

Question 5

Define pressure.

Accepted Answer

Pressure is the force exerted

Question 6

If NO and NH3 are allowed to effuse through a porous membrane under identical conditions,the rate of effusion for NH3 will be ________ times that of NO .

Accepted Answer

A)  0.57 
B)  0.75 
C)  1.3 
D)  1.8 
A)  0.57 
B)  0.75 
C)  1.3 
D)  1.8

Question 7

Determine the mass of water formed when 12.5 L NH3 (at 298 K and 1.50 atm)is reacted with 18.9 L of O2 (at 323 K and 1.1 atm). 4 NH3(g)+ 5 O2(g)→ 4 NO(g)+ 6 H2O(g)

Accepted Answer

A)  17.0 g H2O 
B)  20.7 g H2O 
C)  37.7 g H2O 
D)  13.8 g H2O 
E)  27.9 g H2O 
A)  17.0 g H2O 
B)  20.7 g H2O 
C)  37.7 g H2O 
D)  13.8 g H2O 
E)  27.9 g H2O

Question 8

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

Accepted Answer

A)  4.2 atm 
B)  3.7 atm 
C)  1.8 atm 
D)  5.5 atm 
E)  2.4 atm 
A)  4.2 atm 
B)  3.7 atm 
C)  1.8 atm 
D)  5.5 atm 
E)  2.4 atm

Question 9

What is the temperature of NO2 gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

Accepted Answer

A)  1.38 K 
B)  1.04 × 103 K 
C)  1.38 × 103 K 
D)  1.04 × 106 K 
A)  1.38 K 
B)  1.04 × 103 K 
C)  1.38 × 103 K 
D)  1.04 × 106 K

Question 10

The density of an unknown gas at 320K is 3.97 g/L and exerts a pressure of 1.80 atm in a cylinder.What is the gas?

Accepted Answer

A)  F2 
B)  C4H10 
C)  Cl2 
D)  C2H2 
A)  F2 
B)  C4H10 
C)  Cl2 
D)  C2H2

Question 11

Which of the following gases has the lowest average speed at 25°C?

Accepted Answer

A)  C3H8 
B)  Kr    
C)  CH3NH2 
D)  SO2 
A)  C3H8 
B)  Kr    
C)  CH3NH2 
D)  SO2

Question 12

Identify the gas particle that travels the slowest.

Accepted Answer

A)  H2 
B)  O2 
C)  Ne 
D)  F2 
E)  CO 
A)  H2 
B)  O2 
C)  Ne 
D)  F2 
E)  CO

Question 13

The mole fraction of carbon dioxide in dry air near sea level is 0.000375,where the molar mass of carbon dioxide is 44.010.The partial pressure of carbon dioxide when the total atmospheric pressure (dry air)is 97.5 kPa is

Accepted Answer

A)  2.63 × 105 
B)  5.97 × 103 
C)  0.0370 
D)  1.63 
E)  8.40 × 10-4 
A)  2.63 × 105 
B)  5.97 × 103 
C)  0.0370 
D)  1.63 
E)  8.40 × 10-4

Question 14

The density of a gas is 3.16 g/L at STP.What is the gas?

Accepted Answer

A)  H2 
B)  Br2 
C)  Kr  
D)  Cl2 
E)  Ar  
A)  H2 
B)  Br2 
C)  Kr  
D)  Cl2 
E)  Ar

Question 15

Identify the gas particle that travels the fastest.

Accepted Answer

A)  H2 
B)  N2 
C)  Ne 
D)  Cl2 
E)  CO 
A)  H2 
B)  N2 
C)  Ne 
D)  Cl2 
E)  CO

Question 16

What pressure (in atm)will 0.44 moles of CO2 exert in a 2.6 L container at 25°C?

Accepted Answer

A)  0.35 atm 
B)  4.1 atm 
C)  4.7 atm 
D)  8.6 atm 
E)  3.6 atm 
A)  0.35 atm 
B)  4.1 atm 
C)  4.7 atm 
D)  8.6 atm 
E)  3.6 atm

Question 17

A sample of air from a home is found to contain 6.2 ppm of carbon monoxide.This means that if the total pressure is 695 torr,then the partial pressure of CO is ________ torr.

Accepted Answer

A)  4.3 ×   
B)  4.3 ×   
C)  4.3 
D)  8.9 × 103 
E)  1.1 × 108 
A)  4.3 ×   
B)  4.3 ×   
C)  4.3 
D)  8.9 × 103 
E)  1.1 × 108

Question 18

How many molecules of N2 are in a 400.0 mL container at 780 mm Hg and 135°C?

Accepted Answer

A)  7.01 × 1021 molecules 
B)  7.38 × 1021 molecules 
C)  2.12 × 1022 molecules 
D)  2.23 × 1022 molecules 
A)  7.01 × 1021 molecules 
B)  7.38 × 1021 molecules 
C)  2.12 × 1022 molecules 
D)  2.23 × 1022 molecules

Question 19

What is the volume of 30.0 g of argon gas at 157°C and 2.50 kPa pressure?

Accepted Answer

A)  3.87 L 
B)  10.6 L 
C)  393 L 
D)  1070 L 
A)  3.87 L 
B)  10.6 L 
C)  393 L 
D)  1070 L

Question 20

A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 667 torr.Use Boyle's law to calculate the pressure (torr)when the volume is reduced to 7.88 L at a constant temperature of 25.0°C.

Accepted Answer

A)  846 torr 
B)  0.118 torr 
C)  5.26 ×   torr 
D)  526 torr 
E)  1.11 torr 
A)  846 torr 
B)  0.118 torr 
C)  5.26 ×   torr 
D)  526 torr 
E)  1.11 torr

Exam 11: Gases

How many molecules of He are contained in a 10.0 L tank at 7.53 atm and 485 K?

Define hypoxia.

How many liters of oxygen are needed to react with 2.878 g of octane at STP? 2C8H18(g)+ 25O2(g)→ 16CO2(g)+18H2O(g)

If a sample of 0.29 moles of Ar occupies 3.8 L under certain conditions,what volume will 0.66 moles occupy under the same conditions?

Define pressure.

If NO and NH3 are allowed to effuse through a porous membrane under identical conditions,the rate of effusion for NH3 will be ________ times that of NO .

Determine the mass of water formed when 12.5 L NH3 (at 298 K and 1.50 atm)is reacted with 18.9 L of O2 (at 323 K and 1.1 atm). 4 NH3(g)+ 5 O2(g)→ 4 NO(g)+ 6 H2O(g)

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

What is the temperature of NO2 gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

The density of an unknown gas at 320K is 3.97 g/L and exerts a pressure of 1.80 atm in a cylinder.What is the gas?

Which of the following gases has the lowest average speed at 25°C?

Identify the gas particle that travels the slowest.

The mole fraction of carbon dioxide in dry air near sea level is 0.000375,where the molar mass of carbon dioxide is 44.010.The partial pressure of carbon dioxide when the total atmospheric pressure (dry air)is 97.5 kPa is

The density of a gas is 3.16 g/L at STP.What is the gas?

Identify the gas particle that travels the fastest.

What pressure (in atm)will 0.44 moles of CO2 exert in a 2.6 L container at 25°C?

A sample of air from a home is found to contain 6.2 ppm of carbon monoxide.This means that if the total pressure is 695 torr,then the partial pressure of CO is ________ torr.

How many molecules of N2 are in a 400.0 mL container at 780 mm Hg and 135°C?

What is the volume of 30.0 g of argon gas at 157°C and 2.50 kPa pressure?

A fixed amount of gas at 25.0°C occupies a volume of 10.0 L when the pressure is 667 torr.Use Boyle's law to calculate the pressure (torr)when the volume is reduced to 7.88 L at a constant temperature of 25.0°C.

Essentials: Units, Measurements, and Problem Solving

Atoms

The Quantum Mechanical Model of the Atom

Periodic Properties of the Elements

Molecules and Compounds

Chemical Bonding I

Chemical Bonding Ii

Chemical Reactions and Chemical Quantities

Introduction to Solutions and Aqueous Reactions

Thermochemistry

Liquids, Solids, and Intermolecular Forces

Crystalline Solids and Modern Materials

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Free Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry

Transition Metals and Coordination Compounds

Filters

How many molecules of Heare contained in a 10.0 L tank at 7.53 atm and 485 K?

How many liters of oxygen are needed to react with 2.878 g of octane at STP? 2C₈H₁₈(g)+ 25O₂(g)→ 16CO₂(g)+18H₂O(g)

If NOand NH₃ are allowed to effuse through a porous membrane under identical conditions,the rate of effusion for NH₃ will be ________ times that of NO.

Determine the mass of water formed when 12.5 L NH₃ (at 298 K and 1.50 atm)is reacted with 18.9 L of O₂ (at 323 K and 1.1 atm). 4 NH₃(g)+ 5 O₂(g)→ 4 NO(g)+ 6 H₂O(g)

What is the temperature of NO₂ gas if the average speed (actually the root-mean-square speed)of the molecules is 750 m/s?

What pressure (in atm)will 0.44 moles of CO₂ exert in a 2.6 L container at 25°C?

How many molecules of N₂ are in a 400.0 mL container at 780 mm Hg and 135°C?