According to the kinetic theory of gases, gas molecules are in continuous random motion and hence possess kinetic energy.
The average kinetic energy of gas molecules is directly proportional to the absolute temperature of the gas.
Average Kinetic Energy = (3/2) k T
where,
k = Boltzmann constant
T = absolute temperature (K)
As temperature increases, the average kinetic energy of gas molecules increases.
At absolute zero temperature (0 K), the kinetic energy of gas molecules is minimum.
The average kinetic energy per mole of gas molecules is:
Average KE per mole = (3/2) R T
where,
R = universal gas constant
Q1. Gas molecules possess kinetic energy due to: A) Large size B) Intermolecular forces C) Random motion D) High pressure Answer: C Q2. Average kinetic energy of gas molecules depends on: A) Pressure B) Volume C) Temperature D) Mass of gas Answer: C Q3. Formula for average kinetic energy of a gas molecule is: A) (1/2) m v² B) (3/2) k T C) (3/2) R T D) P V Answer: B Q4. Average kinetic energy of gas molecules at the same temperature is: A) Different for different gases B) Same for all gases C) Zero D) Maximum Answer: B Q5. At absolute zero temperature, kinetic energy of gas molecules is: A) Maximum B) Infinite C) Zero D) Minimum Answer: D Q6. The constant k in kinetic energy formula is: A) Universal gas constant B) Gravitational constant C) Boltzmann constant D) Planck constant Answer: C Q7. Average kinetic energy per mole of gas molecules is: A) (1/2) R T B) (3/2) k T C) (3/2) R T D) R T Answer: C Q8. Kinetic energy of gas molecules is independent of: A) Temperature B) Pressure C) Absolute temperature D) Thermal energy Answer: B
Gas molecules possess kinetic energy due to random motion.
Proportional to absolute temperature.
Average KE per molecule = (3/2) k T
Average KE per mole = (3/2) R T
MCQs are frequently asked on relation between kinetic energy and temperature and related formulas.
