One mole of Argon gas is confined to a 1.0 L container at a pressure of 10 atm . What is the rms speed of the argon atoms?

We can express the rms speed of Argon atoms by combining the ideal gas law with the equation for the root mean square velocity of an atom.
The ideal gas law is:
PV=nRT
The rms velocity of a molecule with molar mass M is:
v_(rms)=sqrt((3RT)/M)
From the ideal gas law we have:
RT=(PV)/n
Substitute this into the v_(rms) relation.
v_(rms)=sqrt((3PV)/(nM))
Substitute numerical values and evaluate v_(rms) for Argon atoms.
v_(rms)=sqrt((3(10 atm)(101.325 (kPa)/(atm))(1.0*10^-3 m^3))/((1 mol)(39.948*10^-3 (kg)/(mol))))
v_(rms)=0.28 (km)/s
http://hyperphysics.phy-astr.gsu.edu/hbase/Kinetic/kintem.html