The differential capacitance curves were measured with an ac bridge on liquid dropping (Cd-Ga) electrode in dimethylformamide (DMF) solution of surface -inactive electrolyte and also in the (Cd-Ga) / [DMF + 0.1 m M LiCl + 0.1(1 - m) M LiBF4], (Cd-Ga) / [DMF + 0.1 m M LiBr + 0.1(1 - m) M LiBF4], and (Cd-Ga) / [DMF + 0.1 m M LiI + 0.1(1 - m) M LiBF4] systems at the following values of molar fraction m of the surface-active anion: 0, 0.01, 0.02, 0.05, 0.1, 02, 05, and 1. Electric double layer structure on (Cd-Ga)/DMF, Hg/DMF and Ga/DMF interfaces in solution of surface -inactive electrolyte was compared. It is found that energy of metal-DMF chemisorption interaction increases in the series of Hg < (Cd-Ga) < Ga. The Cl-, Br- and I- (Hal(-)) anions specific adsorption in the above system can be described quantitatively by the Frumkin isotherm. Unlike Hg/DMF and Bi/DMF interfaces, where the values Delta G(ads) increased in the sequence Cl- < Br- < I-, at the (Cd-Ga)/DMF same as Ga/DMF, it increased in the inverse sequence: I- < Br- < Cl-. The obtained results can be used for unambiguous assessment of an increase in the metal -Hal(-) interaction energy in the series of Delta G((Cd-Ga)-I)(-)< Delta G((Cd-Ga)-Br)(-) < Delta G((Cd-Ga)-Cl)(-) and of difference (Delta G((Cd-Ga)-Hal1)(-) -Delta G((Cd-Ga)-Hal2)(-)) exceeding the difference of solvation energies of Hal(-) (Delta G(DMF-Hal1)(-)-Delta D-GMF-Hal2(-)). Transition from Ga/DMF to (Cd-Ga)/DMF is accompanied by a decrease values Mac's. In view of a decrease (Cd-Ga)-DMF chemisorption interaction as compared with Ga-DMF, this result can be explained only by the corresponding decrease of energy metal-Hal(-) interaction at transition from Ga to (Cd-Ga). (C) 2015 Published by Elsevier B.V.