A flow-mixing calorimeter has been used to measure the excess molar enthalpy H-m(E)(p(o)) of (nitrogen + diethyl ketone)(g) at standard atmospheric pressure (p(o)) over the temperature range (373.2 to 423.2) K. The measurements were analysed using pair potential parameters for nitrogen, assuming suitable combining rules for the calculation of cross-terms, and, for diethyl ketone, finding parameters for the Stockmayer potential which fitted the excess enthalpy measurements. These parameters, which are epsilon/k = 720 K, sigma = 0.375 nm, and t* = 0.506, yielded values of the second virial coefficient B for diethyl ketone in satisfactory agreement with other work,