Experimental heats of mixing for gaseous nitrogen and methane

Abstract

Abstract The excess enthalpy of binary gas phase mixtures has been measured by direct experiment, using a continuous flow, isothermal colorimeter. Heat of mixing data are presented for the methane‐nitrogen system for compositions of 25 to 80 mole % methane in nitrogen, at temperatures of 40°, 0°, −20°, −40°, −60°, and −78°C. and pressures from 250 to 1,50 lb./sq. in. abs. These data are in agreement with the literature to within the experimental uncertainty of this work, 4%. The experimental results agree well with values predicted using the Benedict‐Webb‐Rubin and the Redlich‐Kwong equations of state. The virial equation of state truncated after the third coefficient fits the low density data only. The liquid theories of Scott predict the enthalpies of the mixtures in a qualitative way.