The differential capacitance curves were measured with an ac bridge in the Ga/[DMF + 0.1m M LiCl + 0.1(1 - m) M LiClO4], Ga/[DMF + 0.1m M LiBr + 0.1(1 - m) M LiClO4], and Ga/[DMF + 0.1m MLiI + 0.1(1 - m) M LiClO4] systems at the following values of molar fraction m of the surface-active anion: 0, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1. Dimethylformamide (DMF), as well as N-methylformamide (N-MF) allows achieving large positive charges of the Ga electrode, at which it remains ideally polarizable (up to 11 mu C/cm(2)). The Cl-, Br- and I- (Hal(-)) anions specific adsorption in the above system can be described quantitatively by the Frumkin isotherm. The free energy of Cl-, Br- and I- anions adsorption (Delta G(ads)) is a quadratic function of electrode charge. Unlike Hg/DMF and Bi/DMF interfaces, where the values Delta G(ads) increase in the sequence Cl- < Br- < I-, at the Ga/DMF same as Ga/N-MF, it increased in the inverse sequence: I- < Br- < Cl-. It is found that the values of energy of Ga-Hal(-) interaction Delta G(Ga-Hal)(-) grow in the series of Delta G(Ga-I)(-) < Delta G(Ga-Br)(-) < Delta G(Ga-cl)(-). The values of difference (Delta G(Ga-Hal1)(-) - Delta G(Ga-Hal2)(-)) are higher than the values of difference between the Hal(-) solvation energies (Delta G(DMF-Hal1)(-) - Delta G(DMF-Hal2)(-)). Transition from Ga/N-MF to Ga/DMF is accompanied by a significant increase values Delta G(ads). In view of a stronger Ga-DMF interaction as compared with Ga-(N-MF), this result can be explained only by the corresponding decrease of Hal(-) solvation energy in DMF. (C) 2015 Published by Elsevier B.V.