These articles indicate that you cannot synthesize formic acid by oxidation of methanol or formaldehyde with potassium permanganate, as the formic acid would be ozidized further to carbon dioxide and water.
A kinetic study of the autocatalytic permanganate oxidation of formic acid.
Perez-Benito, Joaquin F.; Arias, Conchita; Brillas, Enrique.
Int. J. Chem. Kinet. (1990), 22(3), 261-87.
Abstract
The results of the title study indicate that this reaction is autocatalyzed by both manganese(II) ion (formed as a reaction product) and colloidal manganese dioxide (formed as an intermediate). The apparent rate consts. corresponding to the noncatalytic and autocatalytic reaction pathways are obtained. The activation energies assocd. with the true rate consts. were also derived. The percentage of the total reaction corresponding to each pathway is given for typical exptl. conditions. Mechanisms in agreement with the kinetic data are proposed for the six different reaction pathways obsd.
Conditions for acetic acid purification from formic acid by potassium permanganate or dichromate.
Fedoseeva, Z. K.; Freidlin, G. N.
Khim. Prom. (1956), 306-7.
Abstract
A 5% excess of oxidizing agent over the theoretically required amt. is sufficient for the HCO2H oxidation. Vigorous stirring shortens the reaction and improves the results. A revolution no. in the soln. of 6208, calcd. from the mixer revolution rate, is found to be the optimum for oxidation. A single treatment with KMnO4 or K2Cr2O7 reduces the HCO2H concn. in AcOH to 0.1%, a double treatment to 0.06%. Higher temp. favors the oxidation rate.
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