Question 1

For a gas obeying Boyle's Law, a plot of V versus 1/P will give a straight line passing through the origin.

Accepted Answer

A) True 
 B)False

Question 2

The volume of a single molecule of water is 2.99 × 10-23 mL. For a sample of gaseous water at 1.00 atm and 150°C, what fraction of the container's volume is occupied by the molecules themselves?

Accepted Answer

A)  5.2 × 10-7 
B)  4.5 × 10-5 
C)  5.2 × 10-4 
D)  5.2 × 10-1 
E)  None of these choices are correct. 
A)  5.2 × 10-7 
B)  4.5 × 10-5 
C)  5.2 × 10-4 
D)  5.2 × 10-1 
E)  None of these choices are correct.

Question 3

Which of the following gases will be the slowest to diffuse through a room?

Accepted Answer

A)  methane, CH4 
B)  hydrogen sulfide, H2S 
C)  carbon dioxide, CO2 
D)  water, H2O 
E)  neon, Ne 
A)  methane, CH4 
B)  hydrogen sulfide, H2S 
C)  carbon dioxide, CO2 
D)  water, H2O 
E)  neon, Ne

Question 4

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

Accepted Answer

A) True 
 B)False

Question 5

For a pure gas sample, the average kinetic energy is also the most probable kinetic energy.

Accepted Answer

A) True 
 B)False

Question 6

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 7

Select the statement that does not apply to an ideal gas.

Accepted Answer

A)  There are no attractive forces between the gas molecules. 
B)  There are strong repulsive forces between the gas molecules. 
C)  The volume occupied by the molecules is negligible compared to the container volume. 
D)  The gas behaves according to the ideal gas equation. 
E)  The average kinetic energy of the molecules is proportional to the absolute temperature. 
A)  There are no attractive forces between the gas molecules. 
B)  There are strong repulsive forces between the gas molecules. 
C)  The volume occupied by the molecules is negligible compared to the container volume. 
D)  The gas behaves according to the ideal gas equation. 
E)  The average kinetic energy of the molecules is proportional to the absolute temperature.

Question 8

A sample of the inert gas krypton has its pressure tripled while its temperature remained constant. If the original volume is 12 L, what is the final volume?

Accepted Answer

A)  4.0 L 
B)  6.0 L 
C)  9 L 
D)  36 L 
E)  48 L 
A)  4.0 L 
B)  6.0 L 
C)  9 L 
D)  36 L 
E)  48 L

Question 9

A sample of ammonia gas at 65.5°C and 524 torr has a volume of 15.31 L. What is its volume when the temperature is -15.8°C and its pressure is 524 torr?

Accepted Answer

A)  3.69 L 
B)  11.6 L 
C)  20.2 L 
D)  63.5 L 
E)  not possible, since the volume would have to be negative 
A)  3.69 L 
B)  11.6 L 
C)  20.2 L 
D)  63.5 L 
E)  not possible, since the volume would have to be negative

Question 10

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

Accepted Answer

A)  NH3 
B)  CO 
C)  H2 
D)  SF6 
E)  All the gases have the same root-mean-square molecular speed at 25°C. 
A)  NH3 
B)  CO 
C)  H2 
D)  SF6 
E)  All the gases have the same root-mean-square molecular speed at 25°C.

Question 11

Calculate the pressure of a helium sample at -207.3°C and 768 mL if it exerts a pressure of 175 kPa at 25.0°C and 925 mL.

Accepted Answer

A)  32.1 kPa 
B)  46.6 kPa 
C)  657 kPa 
D)  953 kPa 
E)  not possible, since the pressure would have to be negative 
A)  32.1 kPa 
B)  46.6 kPa 
C)  657 kPa 
D)  953 kPa 
E)  not possible, since the pressure would have to be negative

Question 12

Hydrogen gas exerts a pressure of 466 torr in a container. What is this pressure in atmospheres?

Accepted Answer

A)  0.217 atm 
B)  0.466 atm 
C)  0.613 atm 
D)  1.63 atm 
E)  4.60 atm 
A)  0.217 atm 
B)  0.466 atm 
C)  0.613 atm 
D)  1.63 atm 
E)  4.60 atm

Question 13

A weather balloon was initially at a pressure of 0.950 atm, and its volume was 35.0 L. The pressure decreased to 0.750 atm, without loss of gas or change in temperature. What was the change in the volume?

Accepted Answer

A)  increased by 44.3 L 
B)  increased by 9.3 L 
C)  increased by 7.4 L 
D)  decreased by 27.6 L 
E)  decreased by 7.4 L 
A)  increased by 44.3 L 
B)  increased by 9.3 L 
C)  increased by 7.4 L 
D)  decreased by 27.6 L 
E)  decreased by 7.4 L

Question 14

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 15

Magnesium metal (0.100 mol) and a volume of aqueous hydrochloric acid that contains 0.500 mol of HCl are combined and react to completion. How many liters of hydrogen gas, measured at STP, are produced? Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

Accepted Answer

A)  2.24 L of H2 
B)  4.48 L of H2 
C)  5.60 L of H2 
D)  11.2 L of H2 
E)  22.4 L of H2 
A)  2.24 L of H2 
B)  4.48 L of H2 
C)  5.60 L of H2 
D)  11.2 L of H2 
E)  22.4 L of H2

Question 16

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 17

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 18

A compressed gas cylinder containing 1.50 mol methane has a volume of 3.30 L. What pressure does the methane exert on the walls of the cylinder if its temperature is 25°C?

Accepted Answer

A)  9.00 × 10-2 atm 
B)  0.933 atm 
C)  1.11 atm 
D)  1.70 atm 
E)  11.1 atm 
A)  9.00 × 10-2 atm 
B)  0.933 atm 
C)  1.11 atm 
D)  1.70 atm 
E)  11.1 atm

Question 19

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)  CHCl3 
B)  CH2Cl2 
C)  C2H2Cl2 
D)  C2H3Cl 
E)  CCl4 
A)  CHCl3 
B)  CH2Cl2 
C)  C2H2Cl2 
D)  C2H3Cl 
E)  CCl4

Question 20

A gas consists of 85.7 percent carbon and 14.3 percent hydrogen, by weight. A sample of this gas weighing 0.673 g occupies 729 mL at a pressure of 720.0 mmHg and a temperature of 77°C. Calculate its empirical and molecular formulas.

Accepted Answer

A)  CH, C2H2 
B)  CH2, C2H4 
C)  CH2, C3H6 
D)  CH3, C2H6 
E)  CH4, CH4 
A)  CH, C2H2 
B)  CH2, C2H4 
C)  CH2, C3H6 
D)  CH3, C2H6 
E)  CH4, CH4

Exam 5: Gases and the Kinetic-Molecular Theory

For a gas obeying Boyle's Law, a plot of V versus 1/P will give a straight line passing through the origin.

The volume of a single molecule of water is 2.99 × 10-23 mL. For a sample of gaseous water at 1.00 atm and 150°C, what fraction of the container's volume is occupied by the molecules themselves?

Which of the following gases will be the slowest to diffuse through a room?

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

For a pure gas sample, the average kinetic energy is also the most probable kinetic energy.

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?

Select the statement that does not apply to an ideal gas.

A sample of the inert gas krypton has its pressure tripled while its temperature remained constant. If the original volume is 12 L, what is the final volume?

A sample of ammonia gas at 65.5°C and 524 torr has a volume of 15.31 L. What is its volume when the temperature is -15.8°C and its pressure is 524 torr?

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

Calculate the pressure of a helium sample at -207.3°C and 768 mL if it exerts a pressure of 175 kPa at 25.0°C and 925 mL.

Hydrogen gas exerts a pressure of 466 torr in a container. What is this pressure in atmospheres?

A weather balloon was initially at a pressure of 0.950 atm, and its volume was 35.0 L. The pressure decreased to 0.750 atm, without loss of gas or change in temperature. What was the change in the volume?

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

Magnesium metal (0.100 mol) and a volume of aqueous hydrochloric acid that contains 0.500 mol of HCl are combined and react to completion. How many liters of hydrogen gas, measured at STP, are produced? Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

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.

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

A compressed gas cylinder containing 1.50 mol methane has a volume of 3.30 L. What pressure does the methane exert on the walls of the cylinder if its temperature is 25°C?

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.

A gas consists of 85.7 percent carbon and 14.3 percent hydrogen, by weight. A sample of this gas weighing 0.673 g occupies 729 mL at a pressure of 720.0 mmHg and a temperature of 77°C. Calculate its empirical and molecular formulas.

Keys to Studying 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

The volume of a single molecule of water is 2.99 × 10^-23 mL. For a sample of gaseous water at 1.00 atm and 150°C, what fraction of the container's volume is occupied by the molecules themselves?

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?

Magnesium metal (0.100 mol) and a volume of aqueous hydrochloric acid that contains 0.500 mol of HCl are combined and react to completion. How many liters of hydrogen gas, measured at STP, are produced? Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)