Details

The molar enthalpy is given by:

, (1)

where and are the pure-component enthalpies (kJ/mol), and are the mole fractions of and and is a non-ideal parameter, which can be either a positive or negative value. The excess enthalpy is:

, (2)

where is the enthalpy of an ideal solution.

The change in temperature for adiabatic mixing is a function of the excess enthalpy and the heat capacity of the solution ().

, (3)

where and represent the initial and final temperatures of the solution.

, (4)

. (5)

The molar entropy of an ideal solution is:

. (6)

The excess entropy can be derived from excess Gibbs energy of mixing and an interaction parameter for the two components .

, (7)

. (8)

The partial molar entropies can be found from interactions of a line tangent to the versus curve using equations analogous to equations (4) and (5).