Physical Chemistry I Examination
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Physical chemistry primarily studies:
A. Classification of living organisms
B. The physical principles governing chemical systems
C. Identification of rocks
D. Historical development of chemistry
Answer: B. The physical principles governing chemical systems
Rationale: Physical chemistry applies physics principles such as thermodynamics,
kinetics, and quantum mechanics to chemical systems.
2. The SI unit of amount of substance is:
A. Gram
B. Liter
C. Mole
D. Kelvin
Answer: C. Mole
Rationale: The mole is the SI base unit used to measure the amount of chemical
substance.
3. The ideal gas law is expressed as:
,A. E = mc²
B. PV = nRT
C. F = ma
D. q = mcΔT
Answer: B. PV = nRT
Rationale: The ideal gas law relates pressure, volume, temperature, and number
of moles.
4. In the ideal gas equation, R represents:
A. Reaction rate
B. Radius
C. Gas constant
D. Resistance
Answer: C. Gas constant
Rationale: R is the universal gas constant used in gas calculations.
5. Boyle’s law states that pressure is:
A. Directly proportional to volume
B. Inversely proportional to volume
C. Equal to temperature
D. Independent of volume
Answer: B. Inversely proportional to volume
Rationale: At constant temperature, increasing pressure decreases gas volume.
6. Charles’s law states that gas volume is directly proportional to:
A. Pressure
B. Density
,C. Absolute temperature
D. Mass
Answer: C. Absolute temperature
Rationale: Gas volume increases as Kelvin temperature increases when pressure is
constant.
7. Avogadro’s law states that equal volumes of gases at the same temperature
and pressure contain equal:
A. Masses
B. Densities
C. Numbers of molecules
D. Energies
Answer: C. Numbers of molecules
Rationale: Equal gas volumes under identical conditions contain equal numbers of
particles.
8. The average kinetic energy of gas molecules depends on:
A. Pressure only
B. Volume only
C. Temperature
D. Molecular color
Answer: C. Temperature
Rationale: Temperature measures the average kinetic energy of particles.
9. The assumptions of the ideal gas model include:
A. Molecules strongly attract each other
B. Gas particles have negligible volume
, C. Molecules are stationary
D. Gas particles lose energy after collisions
Answer: B. Gas particles have negligible volume
Rationale: Ideal gas theory assumes particles occupy negligible space and have no
intermolecular forces.
10. Real gases deviate most from ideal behavior at:
A. High temperature and low pressure
B. Low temperature and high pressure
C. High temperature only
D. Low pressure only
Answer: B. Low temperature and high pressure
Rationale: Under these conditions, intermolecular forces and particle volume
become significant.
11. The SI unit of pressure is:
A. Atmosphere
B. Bar
C. Pascal
D. Torr
Answer: C. Pascal
Rationale: The pascal (Pa) is the SI unit of pressure.
12. One atmosphere is approximately equal to:
A. 10 Pa
B. 101325 Pa
C. 100 Pa
D. 1 Pa
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Physical chemistry primarily studies:
A. Classification of living organisms
B. The physical principles governing chemical systems
C. Identification of rocks
D. Historical development of chemistry
Answer: B. The physical principles governing chemical systems
Rationale: Physical chemistry applies physics principles such as thermodynamics,
kinetics, and quantum mechanics to chemical systems.
2. The SI unit of amount of substance is:
A. Gram
B. Liter
C. Mole
D. Kelvin
Answer: C. Mole
Rationale: The mole is the SI base unit used to measure the amount of chemical
substance.
3. The ideal gas law is expressed as:
,A. E = mc²
B. PV = nRT
C. F = ma
D. q = mcΔT
Answer: B. PV = nRT
Rationale: The ideal gas law relates pressure, volume, temperature, and number
of moles.
4. In the ideal gas equation, R represents:
A. Reaction rate
B. Radius
C. Gas constant
D. Resistance
Answer: C. Gas constant
Rationale: R is the universal gas constant used in gas calculations.
5. Boyle’s law states that pressure is:
A. Directly proportional to volume
B. Inversely proportional to volume
C. Equal to temperature
D. Independent of volume
Answer: B. Inversely proportional to volume
Rationale: At constant temperature, increasing pressure decreases gas volume.
6. Charles’s law states that gas volume is directly proportional to:
A. Pressure
B. Density
,C. Absolute temperature
D. Mass
Answer: C. Absolute temperature
Rationale: Gas volume increases as Kelvin temperature increases when pressure is
constant.
7. Avogadro’s law states that equal volumes of gases at the same temperature
and pressure contain equal:
A. Masses
B. Densities
C. Numbers of molecules
D. Energies
Answer: C. Numbers of molecules
Rationale: Equal gas volumes under identical conditions contain equal numbers of
particles.
8. The average kinetic energy of gas molecules depends on:
A. Pressure only
B. Volume only
C. Temperature
D. Molecular color
Answer: C. Temperature
Rationale: Temperature measures the average kinetic energy of particles.
9. The assumptions of the ideal gas model include:
A. Molecules strongly attract each other
B. Gas particles have negligible volume
, C. Molecules are stationary
D. Gas particles lose energy after collisions
Answer: B. Gas particles have negligible volume
Rationale: Ideal gas theory assumes particles occupy negligible space and have no
intermolecular forces.
10. Real gases deviate most from ideal behavior at:
A. High temperature and low pressure
B. Low temperature and high pressure
C. High temperature only
D. Low pressure only
Answer: B. Low temperature and high pressure
Rationale: Under these conditions, intermolecular forces and particle volume
become significant.
11. The SI unit of pressure is:
A. Atmosphere
B. Bar
C. Pascal
D. Torr
Answer: C. Pascal
Rationale: The pascal (Pa) is the SI unit of pressure.
12. One atmosphere is approximately equal to:
A. 10 Pa
B. 101325 Pa
C. 100 Pa
D. 1 Pa
