SOLUTIONS MANUAL ATKINS PHYSICAL
CHEMISTRY 12TH EDITION BY ATKINS ALL
19 CHAPTERS COVERED BY PETER ATKINS
JULIO DE PAULA AND JAMES KEELER
UPDATED 2026
,TABLE OF CONTENT
1. Focus 1: The properties of gases
2. Focus 2: The First Law
3. Focus 3: The Second and Third Laws
4. Focus 4: Physical transformations of pure substances
5. Focus 5: Simple mixtures
6. Focus 6: Chemical equilibrium
7. Focus 7: Quantum theory
8. Focus 8: Atomic structure and spectra
9. Focus 9: Molecular structure
10. Focus 10: Molecular symmetry
11. Focus 11: Molecular spectroscopy
12. Focus 12: Magnetic resonance
13. Focus 13: Statistical thermodynamics
14. Focus 14: Molecular interactions
15. Focus 15: Solids
16. Focus 16: Molecules in motion
17. Focus 17: Chemical kinetics
18. Focus 18: Reaction dynamics
19. Focus 19: Processes at solid surfaces
,CHAPTER 1: THE PROPERTIES OF GASES
This chapter explores gas behavior through kinetic molecular theory, gas laws, and real
versus ideal gas deviations. Key concepts include pressure, volume, temperature
relationships, diffusion, effusion, and molar mass determination. Understanding these
principles allows chemists to predict gas behavior, apply stoichiometry in reactions, calculate
densities, and address practical laboratory and industrial gas handling safely and accurately.
1. Which law relates pressure and volume of a gas at constant temperature?
A. Charles’ Law
B. Boyle’s Law
C. Avogadro’s Law
D. Gay-Lussac’s Law
Correct Answer: B
Rationale: Boyle’s Law states that pressure is inversely proportional to volume at
constant temperature; other laws relate temperature or moles to volume or pressure.
2. A 2.0 L container of gas at 1.0 atm is compressed to 1.0 L at constant temperature.
What is the new pressure?
A. 0.5 atm
B. 1.0 atm
C. 2.0 atm
D. 4.0 atm
Correct Answer: C
Rationale: Using Boyle’s Law (P1V1 = P2V2), pressure doubles when volume is
halved at constant temperature.
3. At constant pressure, which variable is directly proportional to gas volume?
A. Temperature
B. Pressure
C. Moles
D. Density
Correct Answer: A
Rationale: Charles’ Law states that gas volume increases linearly with temperature at
constant pressure; density and moles are not directly involved in this relation.
4. A gas has a volume of 3.0 L at 300 K. If heated to 450 K at constant pressure, what is
the new volume?
A. 2.0 L
B. 4.5 L
C. 3.5 L
D. 6.0 L
Correct Answer: B
Rationale: Charles’ Law: V1/T1 = V2/T2 → V2 = (3.0 × 450)/300 = 4.5 L.
5. Which gas law involves the relationship between pressure and temperature at constant
volume?
A. Boyle’s Law
B. Charles’ Law
C. Gay-Lussac’s Law
D. Avogadro’s Law
Correct Answer: C
Rationale: Gay-Lussac’s Law states that pressure is directly proportional to
temperature at constant volume.
, 6. One mole of an ideal gas occupies 22.4 L at STP. Which principle is used?
A. Dalton’s Law
B. Ideal Gas Law
C. Graham’s Law
D. Raoult’s Law
Correct Answer: B
Rationale: The Ideal Gas Law (PV = nRT) calculates molar volume at STP; Dalton’s
and Graham’s laws are unrelated to molar volume.
7. Two gases at the same temperature and pressure have equal volumes. What can be
inferred?
A. Different moles
B. Same number of molecules
C. Different densities
D. Different temperatures
Correct Answer: B
Rationale: Avogadro’s Law states equal volumes of gases at the same T and P contain
equal molecules, regardless of identity.
8. A gas mixture exerts a total pressure of 3 atm. If one component exerts 1 atm, what is
the partial pressure of the other?
A. 1 atm
B. 2 atm
C. 3 atm
D. 4 atm
Correct Answer: B
Rationale: Dalton’s Law: total pressure is sum of partial pressures; other component
must be 3 – 1 = 2 atm.
9. Gas A effuses twice as fast as gas B at the same temperature. What is true about their
molar masses?
A. MA = MB
B. MA = 4MB
C. MA = 0.25 MB
D. MA = 2MB
Correct Answer: C
Rationale: Graham’s Law: rate ∝ 1/√M → if rate A is 2×B, √MB/√MA = 2 → MA =
0.25 MB.
10. Which factor does NOT affect the rate of gas diffusion?
A. Molar mass
B. Temperature
C. Pressure
D. Concentration gradient
Correct Answer: C
Rationale: Diffusion rate depends on temperature, molar mass, and gradient; total
pressure alone does not directly change rate.
11. A 1.0 L gas sample at 2 atm is expanded to 3.0 L. Temperature remains constant. New
pressure is?
A. 0.67 atm
B. 6.0 atm
C. 2.0 atm
D. 1.5 atm
CHEMISTRY 12TH EDITION BY ATKINS ALL
19 CHAPTERS COVERED BY PETER ATKINS
JULIO DE PAULA AND JAMES KEELER
UPDATED 2026
,TABLE OF CONTENT
1. Focus 1: The properties of gases
2. Focus 2: The First Law
3. Focus 3: The Second and Third Laws
4. Focus 4: Physical transformations of pure substances
5. Focus 5: Simple mixtures
6. Focus 6: Chemical equilibrium
7. Focus 7: Quantum theory
8. Focus 8: Atomic structure and spectra
9. Focus 9: Molecular structure
10. Focus 10: Molecular symmetry
11. Focus 11: Molecular spectroscopy
12. Focus 12: Magnetic resonance
13. Focus 13: Statistical thermodynamics
14. Focus 14: Molecular interactions
15. Focus 15: Solids
16. Focus 16: Molecules in motion
17. Focus 17: Chemical kinetics
18. Focus 18: Reaction dynamics
19. Focus 19: Processes at solid surfaces
,CHAPTER 1: THE PROPERTIES OF GASES
This chapter explores gas behavior through kinetic molecular theory, gas laws, and real
versus ideal gas deviations. Key concepts include pressure, volume, temperature
relationships, diffusion, effusion, and molar mass determination. Understanding these
principles allows chemists to predict gas behavior, apply stoichiometry in reactions, calculate
densities, and address practical laboratory and industrial gas handling safely and accurately.
1. Which law relates pressure and volume of a gas at constant temperature?
A. Charles’ Law
B. Boyle’s Law
C. Avogadro’s Law
D. Gay-Lussac’s Law
Correct Answer: B
Rationale: Boyle’s Law states that pressure is inversely proportional to volume at
constant temperature; other laws relate temperature or moles to volume or pressure.
2. A 2.0 L container of gas at 1.0 atm is compressed to 1.0 L at constant temperature.
What is the new pressure?
A. 0.5 atm
B. 1.0 atm
C. 2.0 atm
D. 4.0 atm
Correct Answer: C
Rationale: Using Boyle’s Law (P1V1 = P2V2), pressure doubles when volume is
halved at constant temperature.
3. At constant pressure, which variable is directly proportional to gas volume?
A. Temperature
B. Pressure
C. Moles
D. Density
Correct Answer: A
Rationale: Charles’ Law states that gas volume increases linearly with temperature at
constant pressure; density and moles are not directly involved in this relation.
4. A gas has a volume of 3.0 L at 300 K. If heated to 450 K at constant pressure, what is
the new volume?
A. 2.0 L
B. 4.5 L
C. 3.5 L
D. 6.0 L
Correct Answer: B
Rationale: Charles’ Law: V1/T1 = V2/T2 → V2 = (3.0 × 450)/300 = 4.5 L.
5. Which gas law involves the relationship between pressure and temperature at constant
volume?
A. Boyle’s Law
B. Charles’ Law
C. Gay-Lussac’s Law
D. Avogadro’s Law
Correct Answer: C
Rationale: Gay-Lussac’s Law states that pressure is directly proportional to
temperature at constant volume.
, 6. One mole of an ideal gas occupies 22.4 L at STP. Which principle is used?
A. Dalton’s Law
B. Ideal Gas Law
C. Graham’s Law
D. Raoult’s Law
Correct Answer: B
Rationale: The Ideal Gas Law (PV = nRT) calculates molar volume at STP; Dalton’s
and Graham’s laws are unrelated to molar volume.
7. Two gases at the same temperature and pressure have equal volumes. What can be
inferred?
A. Different moles
B. Same number of molecules
C. Different densities
D. Different temperatures
Correct Answer: B
Rationale: Avogadro’s Law states equal volumes of gases at the same T and P contain
equal molecules, regardless of identity.
8. A gas mixture exerts a total pressure of 3 atm. If one component exerts 1 atm, what is
the partial pressure of the other?
A. 1 atm
B. 2 atm
C. 3 atm
D. 4 atm
Correct Answer: B
Rationale: Dalton’s Law: total pressure is sum of partial pressures; other component
must be 3 – 1 = 2 atm.
9. Gas A effuses twice as fast as gas B at the same temperature. What is true about their
molar masses?
A. MA = MB
B. MA = 4MB
C. MA = 0.25 MB
D. MA = 2MB
Correct Answer: C
Rationale: Graham’s Law: rate ∝ 1/√M → if rate A is 2×B, √MB/√MA = 2 → MA =
0.25 MB.
10. Which factor does NOT affect the rate of gas diffusion?
A. Molar mass
B. Temperature
C. Pressure
D. Concentration gradient
Correct Answer: C
Rationale: Diffusion rate depends on temperature, molar mass, and gradient; total
pressure alone does not directly change rate.
11. A 1.0 L gas sample at 2 atm is expanded to 3.0 L. Temperature remains constant. New
pressure is?
A. 0.67 atm
B. 6.0 atm
C. 2.0 atm
D. 1.5 atm
