The excess properties of the three mixtures of nitric oxid with methane, krypton, and nitrogen are calculated and compared with experimental values. As nitric oxid is strongly dimerized in the liquid state, the calculation involves the assignment of potential parameters to the nitric oxid monomer and dimer, the statistical mechanical calculation of the excess properties of the fictitious mixtures with monomer and with dimer, and the calculation of the equilibrium properties in the pseudoternary system formed by monomer, dimer, and second component. The comparison with experimental values shows that the calculation gives the correct order of excess values, but fails in some numerical details.