Separative Determination of V^.., V^... and VO^..

Abstract

A fixed amount of the mixed solution of V^... and VO^.. is titrated by normal KMnO₄ solution by which total V is obtained. Another amount of the sample is titrated by KMnO₄ with diphenyl-amine as an indicator by which the amount (in cc) of KMnO₄ solution used would correspond to the amount of V^... and difference in the amount of KMnO₄ used in there two titrations would correspond to the amount of VO^... The mixed solution of V^.. and V^... is titrated by n-KMnO₄ solution by which total V is obtained. Another amount of sample is then taken, silver solution added by which Ag is reduced to Ag and, at the same time, V^.. is oxidized to V^.... After filtering off the precipitated Ag, the solution is titrated by KMnO₄ and the two ions can be quantitatively determined separately from the amount of KMnO₄ used.