The ideal gas law is
PV = n R T

where R = 8.314 J/mole-K .

What is the temperature T of half a mole of H gas in a 3-liter tank at 4 atm of pressure?

Be (very) careful with the units!  

T = 190oC

T = 49oC

T = 19oC

T = 9oC

(c) 2000, Doug Davis; all rights reserved