A two-dimensional lattice model for adsorption of solvent molecules at a metal/electrolyte interface is proposed assuming two configurational states for dipoles. The generalized Ising Hamiltonian incorporating Coulombic effects and nonelectrostatic metal-solvent interaction energies is derived and solved for obtaining the order parameters using tile Bethe approximation. The significance of the formalism as well as the extension to adsorption of neutral organic compounds is indicated.