Question

Which of the gases below has the greatest average kinetic energy at ${25}^{0}C$ and 1 atm?

• A. $Ne$
• B. $Ar$
• C. $CO$
• D. ${CO}_2$
• E. All these gases would have the same average kinetic energy under these conditions.

Answer 1

The correct option is E All these gases would have the same average kinetic energy under these conditions.

Average kinetic energy of a gas molecule is given by the formula $KE$ $=$ $\frac{3}{2}$$kT$, where $KE$ refers to the average kinetic energy, $k$ refers to the Boltzmann constant whose value is same for all the gases and temperature $T$. Thus, we see that the average kinetic energy of a gas molecule is directly proportional to its temperature.

In the above question, since all the gases mentioned are in the same temperature conditions, the average kinetic energy for all will be the same as Kinetic energy depends on temperature.

Hence, option E is the correct answer.