Potentiometric Titration of Manganese (II) with Potassium Ferricyanide using Mannitol as a Complexing Agent

A new method has been proposed for the potentiometric titration of manganese ion with potassium ferricyanide in the presence of mannitol as a complexing agent in a potassium hydroxide medium. The optimum conditions for potentiometric end-point detection were studied as a function of concentration of mannitol, concentration of potassium hydroxide and concentration of manganese(II), under the optimum conditions the titrations are fast and exhibit a reasonable potential change at the equivalence point. Thus, the addition of complexing agent increases the sharpness of endpoint of titration with ferricyanide. The precision and accuracy of the method have been assessed by the application of lack ? of- fit test and other stastical methods. Overall mean recovery and the mean standard analytical errors obtained were 100.06% and 0.0097 respectively.