The Gibbs free energy of mixing for a regular binary solution of components A and B, at temperature T, on the basis of the Margules equation for activity coefficient, is (in standard notation)

Concept:

The Gibbs free energy (G) of a chemical system can be described using the Margules equation, particularly in the context of non-ideal solutions. The Margules equation is a thermodynamic expression that accounts for the deviations from ideal behavior in solutions. It is typically used for binary solutions, where two components are mixed together.

Explanation:

Gibbs free energy when two components A and B are mixed to form binary solution

\(∆G_{mix}=nRT(x_Alnx_A + x_Blnx_B)\)

According to Margules equation,

After mixing of the components A and B, to determine strong interaction of A-B comparison to A-A and B-B bond, coefficient ξ is used which is dimensionless.

\(∆G_{mix}=nRT(x_Alnx_A + x_Blnx_B + ξx_AX_B) \)

Conclusion:

The Gibbs free energy on the basis of Margules equation is \(∆G_{mix}=nRT(x_Alnx_A + x_Blnx_B + ξx_AX_B) \).