Question 1

A gas occupies 3.33 L at 2.23 bar. What is the volume at 2.50 bar?

Accepted Answer

A)  1.67 L 
B)  3.73 L 
C)  2.97 L 
D)  0.268 L 
E)  18.6 L 
A)  1.67 L 
B)  3.73 L 
C)  2.97 L 
D)  0.268 L 
E)  18.6 L C

Question 2

Which of the following samples has the greatest density at STP?

Accepted Answer

A)  NO2 
B)  Xe 
C)  SO2 
D)  SF6 
E)  All of these samples have the same density at STP. 
A)  NO2 
B)  Xe 
C)  SO2 
D)  SF6 
E)  All of these samples have the same density at STP. D

Question 3

Match the following.
-barometer

Accepted Answer

A) PV = nRT 
B) V1/T1 = V2/T2 
C) V1/n1 = V2/n2 
D) PT = PA + PB + PC ... 
E) measures pressure of a gas
F)measures atmospheric pressure
G)measures blood pressure
H)P1V1 = P2V2 
A) PV = nRT 
B) V1/T1 = V2/T2 
C) V1/n1 = V2/n2 
D) PT = PA + PB + PC ... 
E) measures pressure of a gas
F)measures atmospheric pressure
G)measures blood pressure
H)P1V1 = P2V2 F

Question 4

Calculate the molecular weight of a gas that has a root mean square velocity of 269 m s-1 at 381 K.

Accepted Answer

A)  131 g mol-1 
B)  83.8 g mol-1 
C)  39.9 g mol-1 
D)  20.2 g mol-1 
E)  4.00 g mol-1 
A)  131 g mol-1 
B)  83.8 g mol-1 
C)  39.9 g mol-1 
D)  20.2 g mol-1 
E)  4.00 g mol-1

Question 5

Calculate the ratio of effusion rates of Cl2 to F2.

Accepted Answer

A)  1.3661 
B)  0.53588 
C)  1.8661 
D)  0.28716 
E)  0.73204 
A)  1.3661 
B)  0.53588 
C)  1.8661 
D)  0.28716 
E)  0.73204

Question 6

Define pressure.

Accepted Answer

Pressure is the force exerted

Question 7

If NO2 and NH3 are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH3 will be ________ times that of NO2.

Accepted Answer

A)  0.37 
B)  0.61 
C)  1.6 
D)  2.7 
A)  0.37 
B)  0.61 
C)  1.6 
D)  2.7

Question 8

How many molecules of CO2 are contained in a 10.0 L tank at 7.53 bar and 485 K?

Accepted Answer

A)  1.89 × 1024 molecules 
B)  1.12 × 1024 molecules 
C)  8.32 × 1024 molecules 
D)  4.89 × 1024 molecules 
E)  3.63 × 1024 molecules 
A)  1.89 × 1024 molecules 
B)  1.12 × 1024 molecules 
C)  8.32 × 1024 molecules 
D)  4.89 × 1024 molecules 
E)  3.63 × 1024 molecules

Question 9

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 10

A sample of 0.300 moles of nitrogen occupies 0.600 L. Under the same conditions, what number of moles occupies 1.200 L?

Accepted Answer

A)  0.600 moles 
B)  1.50 moles 
C)  0.33 moles 
D)  6.00 moles 
A)  0.600 moles 
B)  1.50 moles 
C)  0.33 moles 
D)  6.00 moles

Question 11

A sample of gas initially has a volume of 859 mL at 565 K and 2.20 bar. What pressure will the sample have if the volume changes to 268 mL while the temperature is increased to 815 K?

Accepted Answer

A)  10.2 bar 
B)  9.83 bar 
C)  15.3 bar 
D)  6.53 bar 
E)  1.05 bar 
A)  10.2 bar 
B)  9.83 bar 
C)  15.3 bar 
D)  6.53 bar 
E)  1.05 bar

Question 12

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

Accepted Answer

A)  He 
B)  SO2 
C)  H2 
D)  N2 
E)  F2 
A)  He 
B)  SO2 
C)  H2 
D)  N2 
E)  F2

Question 13

If a scuba diver inhaled air at 3 bar pressure deep in the water and decided to swim back quickly to the surface while holding her breath, what do you expect would happen?

Accepted Answer

A)  The volume of the air in her lungs would increase by a factor of 3. 
B)  The volume of the air in her lungs would decrease by a factor of 3. 
C)  The volume of the air in her lungs would increase by a factor of 6. 
D)  The volume of the air in her lungs would decrease by a factor of 6. 
E)  The volume of the air in her lungs would not change. 
A)  The volume of the air in her lungs would increase by a factor of 3. 
B)  The volume of the air in her lungs would decrease by a factor of 3. 
C)  The volume of the air in her lungs would increase by a factor of 6. 
D)  The volume of the air in her lungs would decrease by a factor of 6. 
E)  The volume of the air in her lungs would not change.

Question 14

Which of the following statements is TRUE?

Accepted Answer

A)  Root mean square velocity is directly proportional to the molar mass of the gas. 
B)  Smaller gas particles move more quickly than the larger ones. 
C)  Smaller particles move more slowly than the larger ones. 
D)  The molar mass of the particles has no impact on the root mean velocity. 
E)  Mean free path increases with increasing pressure. 
A)  Root mean square velocity is directly proportional to the molar mass of the gas. 
B)  Smaller gas particles move more quickly than the larger ones. 
C)  Smaller particles move more slowly than the larger ones. 
D)  The molar mass of the particles has no impact on the root mean velocity. 
E)  Mean free path increases with increasing pressure.

Question 15

What volume will 4.91 × 1022 atoms of Ne occupy at STP?

Accepted Answer

A)  1.10 L 
B)  2.00 L 
C)  2.24 L 
D)  3.11 L 
E)  1.85 L 
A)  1.10 L 
B)  2.00 L 
C)  2.24 L 
D)  3.11 L 
E)  1.85 L

Question 16

The density of a gas is 1.146 g   at STP. What is the gas?

Accepted Answer

A)  He 
B)  O2 
C)      
D)    
A)  He 
B)  O2 
C)      
D)

Question 17

A gas mixture consists of N2, O2, and Ne, where the mole fraction of N2 is 0.55 and the mole fraction of Ne is 0.25. If the mixture is at STP in a 5.0 L container, how many molecules of O2 are present?

Accepted Answer

A)  4.5 × 1022 molecules O2 
B)  2.7 × 1022 molecules O2 
C)  3.7 × 1023 molecules O2 
D)  1.1 × 1023 molecules O2 
E)  9.3 × 1024 molecules O2 
A)  4.5 × 1022 molecules O2 
B)  2.7 × 1022 molecules O2 
C)  3.7 × 1023 molecules O2 
D)  1.1 × 1023 molecules O2 
E)  9.3 × 1024 molecules O2

Question 18

What volume (in mL) will a sample of F2 gas occupy in a syringe at 5.57 bar if the F2 has a volume of 25.0 mL at 1.22 bar?

Accepted Answer

A)  11 mL 
B)  17 mL 
C)  3.8 mL 
D)  5.5 mL 
E)  7.6 mL 
A)  11 mL 
B)  17 mL 
C)  3.8 mL 
D)  5.5 mL 
E)  7.6 mL

Question 19

Using the graph below, determine the gas that has the lowest density at STP.

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  All of the gases have the same density at STP. 
A)  A 
B)  B 
C)  C 
D)  D 
E)  All of the gases have the same density at STP.

Question 20

An unknown gas has a root mean square velocity of 332 m s-1 at 313 K. Identify the unknown gas.

Accepted Answer

A)  Kr 
B)  O2 
C)  Ar 
D)  F2 
E)  Cl2 
A)  Kr 
B)  O2 
C)  Ar 
D)  F2 
E)  Cl2

Exam 5: Gases

A gas occupies 3.33 L at 2.23 bar. What is the volume at 2.50 bar?

Which of the following samples has the greatest density at STP?

Match the following. -barometer

Calculate the molecular weight of a gas that has a root mean square velocity of 269 m s-1 at 381 K.

Calculate the ratio of effusion rates of Cl2 to F2.

Define pressure.

If NO2 and NH3 are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH3 will be ________ times that of NO2.

How many molecules of CO2 are contained in a 10.0 L tank at 7.53 bar and 485 K?

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

A sample of 0.300 moles of nitrogen occupies 0.600 L. Under the same conditions, what number of moles occupies 1.200 L?

A sample of gas initially has a volume of 859 mL at 565 K and 2.20 bar. What pressure will the sample have if the volume changes to 268 mL while the temperature is increased to 815 K?

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

If a scuba diver inhaled air at 3 bar pressure deep in the water and decided to swim back quickly to the surface while holding her breath, what do you expect would happen?

Which of the following statements is TRUE?

What volume will 4.91 × 1022 atoms of Ne occupy at STP?

The density of a gas is 1.146 g at STP. What is the gas?

A gas mixture consists of N2, O2, and Ne, where the mole fraction of N2 is 0.55 and the mole fraction of Ne is 0.25. If the mixture is at STP in a 5.0 L container, how many molecules of O2 are present?

What volume (in mL) will a sample of F2 gas occupy in a syringe at 5.57 bar if the F2 has a volume of 25.0 mL at 1.22 bar?

Using the graph below, determine the gas that has the lowest density at STP.

An unknown gas has a root mean square velocity of 332 m s-1 at 313 K. Identify the unknown gas.

Units of Measurement for Physical and Chemical Change

Atoms and Elements

Molecules, Compounds, and Nomenclature

Chemical Reactions and Stoichiometry

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Gibbs Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry I: Structures

Organic Chemistry Ii: Reactions

Biochemistry

Chemistry of the Nonmetals

Metals and Metallurgy

Transition Metals and Coordination Compounds

Filters

Calculate the molecular weight of a gas that has a root mean square velocity of 269 m s^-1 at 381 K.

Calculate the ratio of effusion rates of Cl₂ to F₂.

If NO₂ and NH₃ are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH₃ will be ________ times that of NO₂.

How many molecules of CO₂ are contained in a 10.0 L tank at 7.53 bar and 485 K?

What volume will 4.91 × 10²²atoms of Ne occupy at STP?

A gas mixture consists of N₂, O₂, and Ne, where the mole fraction of N₂ is 0.55 and the mole fraction of Ne is 0.25. If the mixture is at STP in a 5.0 L container, how many molecules of O₂ are present?

What volume (in mL) will a sample of F₂ gas occupy in a syringe at 5.57 bar if the F₂ has a volume of 25.0 mL at 1.22 bar?

An unknown gas has a root mean square velocity of 332 m s^-1 at 313 K. Identify the unknown gas.