Simple RMS velocity question, what's wrong with my answer?

[couchpotato]

Find the rms speed for an argon atom if 1.5 mol of the gas is confined to a 5.6 liter container at a pressure of 5.5 atm.

PV = nRT
RT = PV/n
v_RMS = \sqrt (3RT/M)

= \sqrt (3PV/nM)

= \sqrt ((3 * (5.5atm * 101.325kPA/atm) * (5.6 * 10^-3 m^3) / (1.5 mol * 39.948 * 10^-3)

= 12.5 m/s

However this is apparently wrong. Can someone please tell me what I went wrong?

Thanks

 

[Philip Wood]

Your substitutions are correct, but you've slipped a factor of 1000 (possibly the k in kPa) in your working out. This becomes a factor of sqrt (1000).

 

[couchpotato]

Thank you!