Selected MCQ

Current Question
Which gas deviates most from ideal behavior at high pressure and low temperature?
  • A. One with negligible intermolecular attraction and molecular volume
  • B. One with significant intermolecular attractions and finite molecular volume
  • C. A hypothetical point-particle gas
  • D. Any gas behaves ideally under all conditions
Correct Answer: B
Explanation:
Real-gas deviations become strong when attractions and excluded volume matter.
Related Question 1
Which layer has highest temperature?
  • A. Troposphere
  • B. Stratosphere
  • C. Thermosphere
  • D. Mesosphere
Correct Answer: C
Explanation:
Thermosphere has very high temperatures.
Related Question 2
Which thermodynamic potential is minimized at constant temperature and pressure?
  • A. Internal energy
  • B. Helmholtz free energy
  • C. Gibbs free energy
  • D. Enthalpy
Correct Answer: C
Explanation:
Gibbs free energy reaches minimum at equilibrium under constant T and P.
Related Question 3
For an ideal gas undergoing adiabatic free expansion into vacuum, the temperature change is:
  • A. Always increases
  • B. Always decreases
  • C. Remains unchanged
  • D. Depends only on volume ratio, not gas type
Correct Answer: C
Explanation:
For an ideal gas, internal energy depends only on temperature and does not change in free expansion.
Related Question 4
Which instrument measures air pressure?
  • A. Hygrometer
  • B. Barometer
  • C. Thermometer
  • D. Anemometer
Correct Answer: B
Explanation:
Barometer measures pressure.
Related Question 5
Which atmospheric layer has lowest temperature?
  • A. Troposphere
  • B. Stratosphere
  • C. Mesosphere
  • D. Thermosphere
Correct Answer: C
Explanation:
Mesosphere is coldest.