(1) The decomposition of aqueous solutions of oxalic acid (0.10, 0.05 and 0.025 N) due to oxidation accelerated by colloidal platinum obtained through the process of dialysis of colloidal platinum-carbonyl was investigated, in the presence of oxygen and diffused day-light, during a period extending over thirty hours at 50.0°C. (2) It appears that the greater part of the course of reaction proceeds in accordance with the formula for the type of zero order after it passed incipiently through a short period of transition and the rate of reaction is scarcely influenced by the concentration of reacting solution. (3) It was definitely shown that the reaction should be retarded if the supply of oxygen is cut off. (4) The above results were explained in conformity with the mechanism of reaction previously proposed.
(1) The influences of gases such as oxygen, nitrogen as well as air under reduced pressure upon the decomposition of aqueous solution of oxalic acid (0.05 N) were, in the existence of colloidal platinum obtained from colloidal platinum-carbonyl through dialysis and under diffused daylight, examined at 50.0°C. (2) Oxygen alone has a marked effect in accelerating the decomposition, but the two others none. (3) This gives support to the mechanism of reaction previously discussed.