A STUDY OF ELECTROLYTIC OXIDATION OF CHROMIC SULPHATE TO CHROMATE OR BICHROMATE. PART I. POTENTIOMETRIC STUDY OF ELECTROLYTE

The nature of the reaction at the anode causing oxidation of trivalent chromium to hexavalent form is studied potentiometrically. Potentials set up on platinum by solu­tions made up of various combinations of the three reactants CrO₄". Cr^... and H^. ions are measured and the values of E_o, obtained by using the various equations showing the mechanism of reaction, are tabulated. Those obtained by using equation.

\(E = E_o+{RT \over NF} [ln(Cr_2O_7^{''}+14ln(H^.)-2ln(Cr^{...})]\) are found to be most constant (average +1.232 volts).