pH standardization of 0.05 mol•kg-1 tetraoxalate buffer:: Application of the Pitzer formalism

With the aim to surpass the concentration limit imposed by the Bates-Guggenheim convention, the Pitzer formalism has been applied to the analysis of the standardization of the pH buffer, potassium tetraoxalate dihydrate. Following the same procedure that has been conventionally applied to other pH buffers,., hydrogen electrodes have been used to measure the potential differences of Harned cells, which contained 0.05 mol.kg(-1) potassium tetraoxalate and up to 1 mol.kg(-1) KCI, at 25 degreesC. A value of pH = 1.650 has been calculated. Another simpler model for activity coefficients, the Guggenheim specific interaction theory, has been found to be inadequate to model this complex system.