The methodology for deriving the differential capacitance at electrochemical interfaces using quasi-chemical approximation is demonstrated for adsorption of solvent dipoles in two configurational states. Explicit results for dipole potential (g(dip)) and the inner layer capacitance (C-i) are reported. The experimentally observed linear correlation between (1/C-i) and g(dip), the negative temperature coefficient of the dipole potential at the potential of zero charge, and the occurrence of capacitance maximum at positive charge densities are discussed.