Average Translational Kinetic Energy: P & V Given

[hairey94]

Homework Statement

The pressure of a 0.02 m3 monoatomic gas in a container is 2 atm. The mass of each atom is 3.351 x 10^-23 g. Calculate the average translational kinetic energy of the gas.

Relevant Equations

Ktr = (3/2) (R/NA) T = (3/2)kT
U = NKtr = (3/2) nRT = (3/2)NkT

If this question asked for internal energy, then it is a straightforward thing, just use the formula U = (3/2) nRT = (3/2) PV. But the question specifically asked for average translational kinetic energy which I'm stuck with the value of T to plug in into the formula as the question only give us P and V. So no value for n and T.

 

[Charles Link]

I think they might want you to calculate the average kinetic energy of an atom of the gas, but it's slightly unclear. They should have specified a temperature also. Using room temperature $T=295$ K might be a good assumption.
The mass of each atom appears to be extra information, that is not needed to solve the problem, but it will tell you what type of gas. What is the mass of a proton or neutron? You can compute the atomic weight, and then determine what gas it is.