Excess enthalpies along isotherm/isobars for binary mixtures of liquid neopentane, SnCl4, and TiCl4, in supercritical CO2 are correlated with two equations of state. Both equations use a Percus-Yevick hard-sphere repulsive pressure term added to an attractive term, and temperature dependent size parameters. One attractive term is empirical, the other is based on a square-well potential. Calculations for pure component enthalpies fit data better than molecular dynamics simulations, but the simulations better predict the excess enthalpies.