What is the average kinetic energy of the molecules in a gas at 273K?

1 Answer
Jul 31, 2014

The average kinetic energy of the molecules is 5.66 × 10⁻²¹ J.

According to Kinetic Molecular Theory, the average kinetic energy of gas molecules is a function only of temperature.

The formula is

#KE = 3/2kT#

where #T# is the Kelvin temperature and #k# is Boltzmann's constant.

#KE = 3/2 × 1.381 × 10⁻²³ "J·K⁻¹" × 273"K"# = 5.66 × 10⁻²¹ J

For a mole of molecules, the average kinetic energy is

#(5.66 × 10⁻²¹"J")/(1"molecule") × (6.022 × 10²³"molecules")/(1"mol")# = 3.41 ×10³ J/mol = 3.41 kJ/mol