COM POSITION OF PRUSSIAN BLUE (FERRIC FERROCYANIDE) BY THERMOMETRIC METHOD

The composition of Prussian blue has been investigated by the method of thermometric titrations between ferric chloride and potassium ferrocyanide at several concentrations of these reactants. From the breaks In the direct titration carves, the composition of ferric ferrocyanide corresponds to KFe[Fe(CN)₆]₃ which with excess of FeCl₃ changes to Fe₄[Fe(CN)₆]₃, whereas the reverse titrations suggest the formation of only one compound, KFe[Fe(CN)6].