ON THE OXIDATION OF STANNOUS CHLORIDE IN SULPHURIC ACID SOLUTION BY AIR AND THE DISSOLUTION VELOCITY OF OXYGEN INTO SULPHURIC ACID SOLUTION

Abstract

Abstract (1) The oxidation velocity of stannous chloride in sulphuric acid solution was observed under quite the same conditions as in the case of the oxidation of the same substance in hydrochloric acid solution, which was reported in the previous paper. The velocity increases slowly as the concentration of sulphuric acid increases as far as it reaches the dissolution velocity of oxygen into the solution, when the concentration of sulphuric acid attains about 0.8 normal, and the further increase of the concentration of sulphuric acid has almost no effect on the oxidation velocity, which was found to be almost independent of the initial concentration of stannous sulphate. The velocity constants, calculated as a zero-order reaction, were approximately expressed as a linear function of the concentration of sulphuric acid. (2) The dissolution velocity of oxygen into sulphuric acid of various concentrations was calculated from the oxidation velocity observed. The dissolution velocity has nearly the same value as that into hydrochloric acid solution under the same conditions. (3) The effect of temperature on the oxidation velocity, when the concentration of sulphuric acid is greater than about 0.8 normal, was ascertained to be negligible under the present conditions.