Question

The average translational kinetic energy of O2 molecules (relative molar mass 32) at a particular temperature is 0.048eV. The translational kinetic energy of N2 molecules (relative molar mass) in eV at the same temperature is?

(a) 0.0015

(b) 0.003

(c) 0.048

(d) 0.768

The question was posed to me during an online interview.

My doubt stems from Gases topic in division Kinetic Theory of Gases of Engineering Physics I

Answer 1

Correct choice is (c) 0.048

To elaborate: Average translational kinetic energy of a molecule=3/2kT

It depends on temperature and not on molecular mass. Hence average translational kinetic energy for N2 will also be 0.048 eV.