ATKINS PHYSICAL CHEMISTRY 12TH EDITION BY ATKINS ALL 19 CHAPTERS
COVERED BY PETER ATKINS JULIO DE PAULA AND JAMES KEELER SOLUTIONS
MANUAL UPDATED 2026 GRADED A
FOCUS 1: THE PROPERTIES OF GASES (Questions 1-25)
Topic 1A: The Perfect Gas
Question 1
According to the perfect gas law (pV = nRT), what pressure would be exerted by
25 g of argon gas (molar mass 39.95 g mol⁻¹) in a 1.5 dm³ container at 30°C?
A) 2.0 bar
B) 5.5 bar
C) 10.5 bar
D) 15.0 bar
Answer: C) 10.5 bar
Rationale: First calculate n = 25 g / 39.95 g mol⁻¹ = 0.626 mol. Then use p = nRT/V
= (0.626 mol) × (8.31 × 10⁻² dm³ bar K⁻¹ mol⁻¹) × (303 K) / (1.5 dm³) = 10.5 bar. The
sample would not exert 2.0 bar as initially suspected .
,Question 2
Boyle's law states that for a fixed amount of gas at constant temperature:
A) p ∝ V
B) pV = constant
C) V ∝ T
D) p ∝ T
Answer: B) pV = constant
Rationale: Boyle's law [1A.4a in Atkins] states that pressure and volume are
inversely proportional at constant temperature, so the product pV remains
constant .
Question 3
A gas sample occupies 2.14 dm³ at 1.97 bar. If the volume is increased to 3.94 dm³
at constant temperature, what is the new pressure?
A) 0.50 bar
B) 1.07 bar
C) 1.97 bar
D) 3.94 bar
,Answer: B) 1.07 bar
Rationale: Using Boyle's law: pᵢVᵢ = p_f V_f → p_f = pᵢVᵢ/V_f = (1.97 bar × 2.14
dm³) / (3.94 dm³) = 1.07 bar .
Question 4
The pressure of a gas in a rigid container at 23°C is 125 kPa. What is the pressure
when the temperature is raised to 110°C?
A) 59.8 kPa
B) 120 kPa
C) 125 kPa
D) 162 kPa
Answer: D) 162 kPa
Rationale: At constant volume, p ∝ T (absolute). p_f = pᵢ × T_f/Tᵢ = 125 kPa × (383
K)/(296 K) = 162 kPa. Note that 23°C = 296 K and 110°C = 383 K .
Question 5
, The partial pressure of a gas in a mixture is defined as:
A) The total pressure divided by the number of gases
B) The pressure the gas would exert if it alone occupied the same container at the
same temperature
C) The pressure due to the gas at its boiling point
D) The difference between total pressure and atmospheric pressure
Answer: B) The pressure the gas would exert if it alone occupied the same
container at the same temperature
Rationale: This is the definition of partial pressure according to Dalton's law. The
total pressure is the sum of partial pressures of all components .
Question 6
A sample of methane (CH₄) has a mass of 0.320 g. How many moles does this
represent? (Molar mass CH₄ = 16.04 g mol⁻¹)
A) 0.0100 mol
B) 0.0150 mol
C) 0.0200 mol
D) 0.0250 mol
COVERED BY PETER ATKINS JULIO DE PAULA AND JAMES KEELER SOLUTIONS
MANUAL UPDATED 2026 GRADED A
FOCUS 1: THE PROPERTIES OF GASES (Questions 1-25)
Topic 1A: The Perfect Gas
Question 1
According to the perfect gas law (pV = nRT), what pressure would be exerted by
25 g of argon gas (molar mass 39.95 g mol⁻¹) in a 1.5 dm³ container at 30°C?
A) 2.0 bar
B) 5.5 bar
C) 10.5 bar
D) 15.0 bar
Answer: C) 10.5 bar
Rationale: First calculate n = 25 g / 39.95 g mol⁻¹ = 0.626 mol. Then use p = nRT/V
= (0.626 mol) × (8.31 × 10⁻² dm³ bar K⁻¹ mol⁻¹) × (303 K) / (1.5 dm³) = 10.5 bar. The
sample would not exert 2.0 bar as initially suspected .
,Question 2
Boyle's law states that for a fixed amount of gas at constant temperature:
A) p ∝ V
B) pV = constant
C) V ∝ T
D) p ∝ T
Answer: B) pV = constant
Rationale: Boyle's law [1A.4a in Atkins] states that pressure and volume are
inversely proportional at constant temperature, so the product pV remains
constant .
Question 3
A gas sample occupies 2.14 dm³ at 1.97 bar. If the volume is increased to 3.94 dm³
at constant temperature, what is the new pressure?
A) 0.50 bar
B) 1.07 bar
C) 1.97 bar
D) 3.94 bar
,Answer: B) 1.07 bar
Rationale: Using Boyle's law: pᵢVᵢ = p_f V_f → p_f = pᵢVᵢ/V_f = (1.97 bar × 2.14
dm³) / (3.94 dm³) = 1.07 bar .
Question 4
The pressure of a gas in a rigid container at 23°C is 125 kPa. What is the pressure
when the temperature is raised to 110°C?
A) 59.8 kPa
B) 120 kPa
C) 125 kPa
D) 162 kPa
Answer: D) 162 kPa
Rationale: At constant volume, p ∝ T (absolute). p_f = pᵢ × T_f/Tᵢ = 125 kPa × (383
K)/(296 K) = 162 kPa. Note that 23°C = 296 K and 110°C = 383 K .
Question 5
, The partial pressure of a gas in a mixture is defined as:
A) The total pressure divided by the number of gases
B) The pressure the gas would exert if it alone occupied the same container at the
same temperature
C) The pressure due to the gas at its boiling point
D) The difference between total pressure and atmospheric pressure
Answer: B) The pressure the gas would exert if it alone occupied the same
container at the same temperature
Rationale: This is the definition of partial pressure according to Dalton's law. The
total pressure is the sum of partial pressures of all components .
Question 6
A sample of methane (CH₄) has a mass of 0.320 g. How many moles does this
represent? (Molar mass CH₄ = 16.04 g mol⁻¹)
A) 0.0100 mol
B) 0.0150 mol
C) 0.0200 mol
D) 0.0250 mol
