The Gibbs–Bogoliubov (GB) inequality is applied to investigate the thermodynamic properties of some equiatomic noble metal alloys in liquid phase such as Au-Cu, Ag-Cu and Ag-Au using well known pseudopotential formalism. For description of the structure, well known Percus-Yevick (PY) hard sphere model is used as a reference system. With this procedure the thermodynamic properties such as entropy and heat of mixing have been computed. The influence of local field correction functions viz; Hartree (HR), Taylor (TY), Ichimaru-Utsumi (IU), Farid et al. (FD) and Sarkar et al. (SS) is also investigated and found successful. The computed results of the excess entropy and the heats of mixing compares are found in qualitative agreement with the available experimental or theoretical data in the literature.