Universal gas constant R
This depends on the units of the measurements used in the ideal gas equation PV=nRT
R then equals PV/nT
If n equals one (for one mole of gas) then
R = PV/T
Using SI units
pressure is measured in Nm2 and the value at atmospheric pressure is 1.01 x 105
temperature is measured in Kelvin = 273 at STP
volume in SI units 22.41 dm3 = 2.241 x 105 m3
R = PV/T = (1.01 x 105 x 2.241 x 105) /273
R = 0.00829
When P is measured in atimospheres, and V is measured in dm3
R = PV/T
R = 1 x 22.41 / 273
R = 0.0821

