Question 1

A carbon dioxide sample weighing 44.0 g occupies 32.68 L at 65°C and 645 torr. What is its volume at STP?

Accepted Answer

A) 22.4 L 
B) 31.1 L 
C) 34.3 L 
D) 35.2 L 
E) 47.7 L 
A) 22.4 L 
B) 31.1 L 
C) 34.3 L 
D) 35.2 L 
E) 47.7 L

Question 2

For real gases, PV > nRT, always.

Accepted Answer

A) True 
 B)False

Question 3

Select the gas with the highest average kinetic energy per mole at 298 K.

Accepted Answer

A) O 2 
B) CO 2 
C) H 2O 
D) H 2 
E) All have the same average kinetic energy. 
A) O 2 
B) CO 2 
C) H 2O 
D) H 2 
E) All have the same average kinetic energy.

Question 4

A sample of propane, a component of LP gas, has a volume of 35.3 L at 315 K and 922 torr. What is its volume at STP?

Accepted Answer

A) 25.2 L 
B) 30.6 L 
C) 33.6 L 
D) 37.1 L 
E) 49.2 L 
A) 25.2 L 
B) 30.6 L 
C) 33.6 L 
D) 37.1 L 
E) 49.2 L

Question 5

Arrange the following gases in order of increasing rate of effusion. C2H6 Ar HCl PH3

Accepted Answer

A) Ar 3 2H 6 
B) C 2H 6 3 3 2H 6 2H 6 3 32H 6 
A) Ar 3 2H 6 
B) C 2H 6 3 3 2H 6 2H 6 3 32H 6

Question 6

Select the gas with the largest root-mean-square molecular speed at 25°C.

Accepted Answer

A) NH 3 
B) CO 
C) H 2 
D) SF 6 
E) All the gases have the same root-mean-square molecular speed at 25°C. 
A) NH 3 
B) CO 
C) H 2 
D) SF 6 
E) All the gases have the same root-mean-square molecular speed at 25°C.

Question 7

The air pressure in a volleyball is 75 psi. What is this pressure in torr?

Accepted Answer

A) 520 torr 
B) 562 torr 
C) 3900 torr 
D) 7600 torr 
E) 75000 torr 
A) 520 torr 
B) 562 torr 
C) 3900 torr 
D) 7600 torr 
E) 75000 torr

Question 8

Calculate the root-mean-square speed of methane, CH4 (g), at 78°C.

Accepted Answer

A) 23 m/s 
B) 350 m/s 
C) 550 m/s 
D) 667 m/s 
E) 740 m/s 
A) 23 m/s 
B) 350 m/s 
C) 550 m/s 
D) 667 m/s 
E) 740 m/s

Question 9

Mercury is 13.6 times as dense as liquid water. What would be the reading of a water-filled barometer at normal atmospheric pressure, 760. mmHg?

Accepted Answer

A) 1.03 × 10 3 torr 
B) 1.03 × 10 3 Pa 
C) 1.03 × 10 3 mm height of water column 
D) 1.03 × 10 3 cm height of water column 
E) 13.6 atm 
A) 1.03 × 10 3 torr 
B) 1.03 × 10 3 Pa 
C) 1.03 × 10 3 mm height of water column 
D) 1.03 × 10 3 cm height of water column 
E) 13.6 atm

Question 10

Which of the following changes will not affect the total pressure of gas in a container, assuming all other factors remain constant?

Accepted Answer

A) The frequency of collisions of molecules with the walls is increased. 
B) The average velocity of the molecules is lowered. 
C) The temperature of the sample is altered. 
D) Half of the molecules are replaced by an equal number of molecules of a gas with a different molecular weight. 
E) The total number of molecules is altered. 
A) The frequency of collisions of molecules with the walls is increased. 
B) The average velocity of the molecules is lowered. 
C) The temperature of the sample is altered. 
D) Half of the molecules are replaced by an equal number of molecules of a gas with a different molecular weight. 
E) The total number of molecules is altered.

Question 11

Linolenic acid (C18H30O2) can be hydrogenated to stearic acid by reacting it with hydrogen gas according to the equation: C18H30O2 + 3H2 → C18H36O2
What volume of hydrogen gas, measured at STP, is required to react with 10.5 g of linolenic acid in this reaction?

Accepted Answer

A) 2.53 L 
B) 1.69 L 
C) 1.27 L 
D) 845 mL 
E) 422 mL 
A) 2.53 L 
B) 1.69 L 
C) 1.27 L 
D) 845 mL 
E) 422 mL

Question 12

At a temperature of absolute zero, the volume of an ideal gas is zero.

Accepted Answer

A) True 
 B)False

Question 13

A compound composed of carbon, hydrogen, and chlorine effuses through a pinhole 0.411 times as fast as neon. Select the correct molecular formula for the compound.

Accepted Answer

A) CHCl 3 
B) CH 2Cl 2 
C) C 2H 2Cl 2 
D) C 2H 3Cl 
E) CCl 4 
A) CHCl 3 
B) CH 2Cl 2 
C) C 2H 2Cl 2 
D) C 2H 3Cl 
E) CCl 4

Question 14

An unknown liquid is vaporized in a 273-mL flask by immersion in a water bath at 99°C. The barometric pressure is 753 torr. If the mass of the vapor retained in the flask is 1.362 g, what is its molar mass?

Accepted Answer

A) 20.4 g/mol 
B) 40.9 g/mol 
C) 112 g/mol 
D) 154 g/mol 
E) 184 g/mol 
A) 20.4 g/mol 
B) 40.9 g/mol 
C) 112 g/mol 
D) 154 g/mol 
E) 184 g/mol

Question 15

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its pressure, other factors remaining constant?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 16

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its absolute temperature, other factors remaining constant?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 17

The pressure of hydrogen sulfide gas in a container is 35,650 Pa. What is this pressure in torr?

Accepted Answer

A) 46.91 torr 
B) 267.4 torr 
C) 351.8 torr 
D) 3612 torr 
E) 27090 torr 
A) 46.91 torr 
B) 267.4 torr 
C) 351.8 torr 
D) 3612 torr 
E) 27090 torr

Question 18

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of __________ Law.

Accepted Answer

A) Charles's 
B) Boyle's 
C) Amontons's 
D) Avogadro's 
E) Dalton's 
A) Charles's 
B) Boyle's 
C) Amontons's 
D) Avogadro's 
E) Dalton's

Question 19

When a closed-ended manometer is used for pressure measurements, and the closed end is under vacuum, the level of manometer liquid in the closed arm can never be lower than that in the other arm.

Accepted Answer

A) True 
 B)False

Question 20

"The total pressure in a mixture of unreacting gases is equal to the sum of the partial pressures of the individual gases" is a statement of __________ Law.

Accepted Answer

A) Charles's 
B) Graham's 
C) Boyle's 
D) Avogadro's 
E) Dalton's 
A) Charles's 
B) Graham's 
C) Boyle's 
D) Avogadro's 
E) Dalton's

Exam 5: Gases and the Kinetic-Molecular Theory

A carbon dioxide sample weighing 44.0 g occupies 32.68 L at 65°C and 645 torr. What is its volume at STP?

For real gases, PV > nRT, always.

Select the gas with the highest average kinetic energy per mole at 298 K.

A sample of propane, a component of LP gas, has a volume of 35.3 L at 315 K and 922 torr. What is its volume at STP?

Arrange the following gases in order of increasing rate of effusion. C2H6 Ar HCl PH3

Select the gas with the largest root-mean-square molecular speed at 25°C.

The air pressure in a volleyball is 75 psi. What is this pressure in torr?

Calculate the root-mean-square speed of methane, CH4 (g), at 78°C.

Mercury is 13.6 times as dense as liquid water. What would be the reading of a water-filled barometer at normal atmospheric pressure, 760. mmHg?

Which of the following changes will not affect the total pressure of gas in a container, assuming all other factors remain constant?

Linolenic acid (C18H30O2) can be hydrogenated to stearic acid by reacting it with hydrogen gas according to the equation: C18H30O2 + 3H2 → C18H36O2 What volume of hydrogen gas, measured at STP, is required to react with 10.5 g of linolenic acid in this reaction?

At a temperature of absolute zero, the volume of an ideal gas is zero.

A compound composed of carbon, hydrogen, and chlorine effuses through a pinhole 0.411 times as fast as neon. Select the correct molecular formula for the compound.

An unknown liquid is vaporized in a 273-mL flask by immersion in a water bath at 99°C. The barometric pressure is 753 torr. If the mass of the vapor retained in the flask is 1.362 g, what is its molar mass?

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its pressure, other factors remaining constant?

Which of the lines on the figure below is the best representation of the relationship between the volume of a gas and its absolute temperature, other factors remaining constant?

The pressure of hydrogen sulfide gas in a container is 35,650 Pa. What is this pressure in torr?

"The volume of an ideal gas is directly proportional to the number of moles of the gas at constant temperature and pressure" is a statement of __________ Law.

When a closed-ended manometer is used for pressure measurements, and the closed end is under vacuum, the level of manometer liquid in the closed arm can never be lower than that in the other arm.

"The total pressure in a mixture of unreacting gases is equal to the sum of the partial pressures of the individual gases" is a statement of __________ Law.

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Arrange the following gases in order of increasing rate of effusion. C₂H₆Ar HCl PH₃

Calculate the root-mean-square speed of methane, CH₄(g), at 78°C.

Linolenic acid (C₁₈H₃₀O₂) can be hydrogenated to stearic acid by reacting it with hydrogen gas according to the equation: C₁₈H₃₀O₂ + 3H₂ → C₁₈H₃₆O₂ What volume of hydrogen gas, measured at STP, is required to react with 10.5 g of linolenic acid in this reaction?