An interactive step-by-step procedure requires the user to identify pure component and mixture enthalpies or entropies in a binary solution. The user determines the excess enthalpy or entropy (differences from an ideal solution). For enthalpies, the user then calculates the temperature change for adiabatic mixing. The partial molar enthalpies and entropies are determined from lines tangent to the enthalpy or entropy curves. Selecting “new problem” at any time resets to step 1 with different numerical values and either an enthalpy or entropy plot randomly selected.