Hi Everyone... I'm trying to calculate the specific gravity of a sample of LNG using a compostion certificate and temperature and pressure variables of 5 bar at -134 deg C saturated. Its do perform a check for the value used to calculate how much is charged per litre by converting density to litres. The density should be around 0.4 kg/m^3 but i cant seem to get a close answer to that using the ideal gas equation, pv = nrt. Infor on composition certificate; Gas composition; Nitrogen ; 1.18% Methane; 96.66% Gas density at 15 deg C = 0.699 k/m^3 Ave MW = 16.487 g/mol Can someone please help? thanks.