Pure component A + classically ideal solution (B + C +⋯)= ?
A recently developed partial ideal solution model has resulted in: a pure component A + a classically ideal solution (B + C +⋯)= a partial ideal solution (A + B + C +⋯).
In this paper, some new formulae are deduced and a much more quantitative verification is made using literature data. The theoretical results are in excellent agreement with room-temperature experiments for organic mixtures, organic–inorganic mixtures and aqueous solutions and in good agreement with high-temperature experimental data for alloys, molten salt mixtures and molten slags. A reasonable prediction is also made for a mixed U + Pu oxide fast-reactor fuel.