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  True

Question 2

A sample container of carbon monoxide occupies a volume of 435 mL at a pressure of 785 torr and a temperature of 298 K. What would its temperature be if the volume were changed to 265 mL at a pressure of 785 torr?

Accepted Answer

A) 182 K 
B) 298 K 
C) 387 K 
D) 489 K 
E) 538 K 
A) 182 K 
B) 298 K 
C) 387 K 
D) 489 K 
E) 538 K A

Question 3

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 A

Question 4

Ima Chemist found the density of Freon-11 (CFCl3) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the unknown?

Accepted Answer

A) 96.7 g/mol 
B) 108 g/mol 
C) 127 g/mol 
D) 165 g/mol 
E) 175 g/mol 
A) 96.7 g/mol 
B) 108 g/mol 
C) 127 g/mol 
D) 165 g/mol 
E) 175 g/mol

Question 5

A sample of oxygen gas has its absolute temperature halved while the pressure of the gas remained constant. If the initial volume is 400 mL, what is the final volume?

Accepted Answer

A) 20 mL 
B) 133 mL 
C) 200 mL 
D) 400 mL 
E) 800 mL 
A) 20 mL 
B) 133 mL 
C) 200 mL 
D) 400 mL 
E) 800 mL

Question 6

The most probable speed of an oxygen molecule in the gas phase at room temperature is 450 m/s. The root-mean-square speed (urms) is therefore

Accepted Answer

A) equal to 450 m/s. 
B) slightly less than 450 m/s. 
C) much less than 450 m/s. 
D) slightly greater than 450 m/s. 
E) much greater than 450 m/s. 
A) equal to 450 m/s. 
B) slightly less than 450 m/s. 
C) much less than 450 m/s. 
D) slightly greater than 450 m/s. 
E) much greater than 450 m/s.

Question 7

For a gas obeying Charles's Law, a plot of V versus 1/T will give a straight line passing through the origin.

Accepted Answer

A) True 
 B)False

Question 8

A sample of nitrogen gas is confined to a 14.0 L container at 375 torr and 37.0°C. How many moles of nitrogen are in the container?

Accepted Answer

A) 0.271 mol 
B) 2.27 mol 
C) 3.69 mol 
D) 206 mol 
E) 227 mol 
A) 0.271 mol 
B) 2.27 mol 
C) 3.69 mol 
D) 206 mol 
E) 227 mol

Question 9

"The volume of an ideal gas is directly proportional to its absolute temperature at constant pressure and number of moles" 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 10

A gas mixture, with a total pressure of 300. torr, consists of equal masses of Ne (atomic weight 20.) and Ar (atomic weight 40.). What is the partial pressure of Ar, in torr?

Accepted Answer

A) 75 torr 
B) 100. torr 
C) 150. torr 
D) 200. torr 
E) None of these choices are correct. 
A) 75 torr 
B) 100. torr 
C) 150. torr 
D) 200. torr 
E) None of these choices are correct.

Question 11

For real gases, PV < nRT, always.

Accepted Answer

A) True 
 B)False

Question 12

Calculate the rms speed of carbon dioxide molecules at STP.

Accepted Answer

A) 12.4 m/s 
B) 155 m/s 
C) 393 m/s 
D) 1.55 × 10 5 m/s 
E) The answer can't be calculated without more data. 
A) 12.4 m/s 
B) 155 m/s 
C) 393 m/s 
D) 1.55 × 10 5 m/s 
E) The answer can't be calculated without more data.

Question 13

According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average kinetic energy.

Accepted Answer

A) True 
 B)False

Question 14

Calculate the temperature of an argon sample at 55.4 kPa and 18.6 L if it occupies 25.8 L at 75.0°C and 41.1 kPa.

Accepted Answer

A) 95.0°C 
B) 85.1°C 
C) 77.2°C 
D) 72.9°C 
E) 65.2°C 
A) 95.0°C 
B) 85.1°C 
C) 77.2°C 
D) 72.9°C 
E) 65.2°C

Question 15

A sample of carbon dioxide gas at 125°C and 248 torr occupies a volume of 275 L. What will the gas pressure be if the volume is increased to 321 L at 125°C?

Accepted Answer

A) 212 torr 
B) 289 torr 
C) 356 torr 
D) 441 torr 
E) 359 torr 
A) 212 torr 
B) 289 torr 
C) 356 torr 
D) 441 torr 
E) 359 torr

Question 16

A 500-mL sample of argon at 800 torr has its absolute temperature quadrupled. If the volume remains unchanged what is the new pressure?

Accepted Answer

A) 200 torr 
B) 400 torr 
C) 800 torr 
D) 2400 torr 
E) 3200 torr 
A) 200 torr 
B) 400 torr 
C) 800 torr 
D) 2400 torr 
E) 3200 torr

Question 17

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 18

Given that pressure has dimensions of force ÷ area; that force has dimensions of mass × acceleration; and that the S.I. unit of pressure is the pascal, what is 1 pascal in terms of S.I. base units?

Accepted Answer

A) 1 Pa = 1000 g/cm·s 2 
B) 1 Pa = 1 g/m·s 2 
C) 1 Pa = 10 −3 kg·m/s 2 
D) 1 Pa = 1 kg·m/s 2 
E) 1 Pa = 1 kg/m·s 2 
A) 1 Pa = 1000 g/cm·s 2 
B) 1 Pa = 1 g/m·s 2 
C) 1 Pa = 10 −3 kg·m/s 2 
D) 1 Pa = 1 kg·m/s 2 
E) 1 Pa = 1 kg/m·s 2

Question 19

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 20

A gas mixture consists of equal masses of methane (molecular weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr?

Accepted Answer

A) 80.0 torr 
B) 200. torr 
C) 256 torr 
D) 500. torr 
E) 556 torr 
A) 80.0 torr 
B) 200. torr 
C) 256 torr 
D) 500. torr 
E) 556 torr

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.

A sample container of carbon monoxide occupies a volume of 435 mL at a pressure of 785 torr and a temperature of 298 K. What would its temperature be if the volume were changed to 265 mL at a pressure of 785 torr?

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?

Ima Chemist found the density of Freon-11 (CFCl3) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the unknown?

A sample of oxygen gas has its absolute temperature halved while the pressure of the gas remained constant. If the initial volume is 400 mL, what is the final volume?

The most probable speed of an oxygen molecule in the gas phase at room temperature is 450 m/s. The root-mean-square speed (urms) is therefore

For a gas obeying Charles's Law, a plot of V versus 1/T will give a straight line passing through the origin.

A sample of nitrogen gas is confined to a 14.0 L container at 375 torr and 37.0°C. How many moles of nitrogen are in the container?

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

A gas mixture, with a total pressure of 300. torr, consists of equal masses of Ne (atomic weight 20.) and Ar (atomic weight 40.). What is the partial pressure of Ar, in torr?

For real gases, PV < nRT, always.

Calculate the rms speed of carbon dioxide molecules at STP.

According to the postulates of kinetic-molecular theory, the molecules of all gases at a given temperature have the same average kinetic energy.

Calculate the temperature of an argon sample at 55.4 kPa and 18.6 L if it occupies 25.8 L at 75.0°C and 41.1 kPa.

A sample of carbon dioxide gas at 125°C and 248 torr occupies a volume of 275 L. What will the gas pressure be if the volume is increased to 321 L at 125°C?

A 500-mL sample of argon at 800 torr has its absolute temperature quadrupled. If the volume remains unchanged what is the new pressure?

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?

Given that pressure has dimensions of force ÷ area; that force has dimensions of mass × acceleration; and that the S.I. unit of pressure is the pascal, what is 1 pascal in terms of S.I. base units?

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

A gas mixture consists of equal masses of methane (molecular weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr?

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

Ima Chemist found the density of Freon-11 (CFCl₃) to be 5.58 g/L under her experimental conditions. Her measurements showed that the density of an unknown gas was 4.38 g/L under the same conditions. What is the molar mass of the unknown?

The most probable speed of an oxygen molecule in the gas phase at room temperature is 450 m/s. The root-mean-square speed (u_rms) is therefore