The solubility of Zn(NH3)(2)Cl-2 in aqueous solutions containing ZnCl2 and NH4Cl at 298.15 K has been determined by pH titration with ZnO. In addition, the curve defining the critical concentrations of free ZnCl2 and free NH4Cl which are in equilibrium at 298.15 K in aqueous solution with precipitates of both Zn(NH3)(2)Cl-2 and ZnCl2 . 4Zn(OH)(2) . H2O has been determined for the first time by a new method involving potentiometric titrations using ZnO as titrant and zinc electrode potential as indicator. The new information has allowed the overall reactions which take place in three or four sequential stages during the discharge of a traditional Leclanche cell to be reviewed and significantly modified. The Gibbs free energies of formation of Zn(NH3)(2)Cl-2 and ZnCl2 . 4Zn(OH)(2) . H2O at 298.15 K have been estimated respectively as -505,375 and -2,896,060 J mol(-1).