1977 Volume 20 Pages 1-9
The purpose of this study is to examine the optimum reaction condition for obtaining the precise kinetics data through a simple procedure. The author compared the catalytic activities of various kinds of ion catalysts, i.e, MoO42-, WO42-, Cr2O72-and Fe3+, with each other. With these catalysts, except Cr2O72-，the reaction rate is proportional to the concentration of hydrogen peroxide 〔H2O2〕with1st order. By Cr2O72-catalyst, the reaction rate is in the -1st order. The activities of MoO42-and WO42- are lower than those of others. Four kinds of Fe3+ catalysts (Fe3+NS, Fe3+S, Fe3+N,and Fe3+ C1) prepared from the different kinds of mother salts, respectively, i. e. ferric nitrate, ferric, chloride, ferric sulfate ammonium and ferric sulfate, were used. The order of the catalytic activity height is Fe3+N (21.3) > Fe3+ C1 (17.4) > Fe3+NS(15.2) > Fe3+S（18.5). The figures in parentheses show the activation energy value by Kcal/mole。With Fe3+NS and Fe3+S catalyst, the reaction rate is, in the comparatively wide range of〔H2O2〕／〔Fe3+〕ratio, expressed as follows : With Fe3+N and Fe3+ C1 catalyst, the reaction rate is in the 1st order with respect to 〔H2O2〕but the rate equation is more complicated. The measurement of initial rate of reaction is considered to be favorable when it is required to obtain the precise kinetics data. In this experiment the author perfomed the reaction under the following conditions so as to easily observe the initial rate of reaction. Reaction temperature was 5~25℃.concentration of hydrogen peroxide was 0.49~0. 51 mole/1, and the amount of catalyst added into the reaction system was 0. 5~4×10-4mole. In the last part of this paper the author surveyed the main theories of the reaction mechanism of H2O2 - Fe3+ system already proposed.
