P. K. Gallagher, D. W. Johnson
Jul 1, 1971
Citations
0
Influential Citations
20
Citations
Journal
Journal of The Electrochemical Society
Abstract
Abstract Isothermal weight studies were performed upon aqueous solutions of manganese(II) nitrate. The loss of water followed a first order rate law with activation energies varying from 6 to 10 kcal/mole depending upon the atmosphere. The resulting anhydrous nitrate decomposed to form manganese(II) oxynitrate in accordance with the Erofeev equation with n = 4. The activation energies are 20–25 kcal/mole and show little variation with atmosphere. The resulting oxynitrate decomposed to form manganese(IV) oxide. The rate fits several expressions satisfactorily but a contracting area form is chosen as generally best. The activation energy is about 12 kcal/mole lower in the presence of moisture but this effect upon the rate is partially offset by a substantial decrease in the preexponential term. The manganese(IV) oxide loses oxygen to form manganese(III) oxide. The best rate law is the Jander equation and activation energies are in the range of 47–57 kcal/mole.