posted by John .
1) what is the density of methane (CH4) at a temp. of 20C and a pressure of 684mm.
2) a gas has a density of 2.5g/L at a temp. of 20C and a pressure of 1.1 atm. what is its molar mass.
I use the modified ideal gas equation for that. PM = dRT
M = molar mass
d = density
T must be in kelvin