Abstract
To examine the reaction process for trichloromethane formation through the chlorination of acetone in the neibourfood of pH=7, acetone was allowed to react with chlorine aqueous solution at 25°C, pH=1-8. The results obtained were as follows : (1) Monochloroacetone was formed at pH=1-5, but 1, 1-dichloroacetone, 1, 1, 1-trichloroacetone and trichloromethane were not detected. (2) At pH=6-7, monochloroacetone, 1, 1, 1-trichloroacetone and trichloromethane were found. (3) At pH=7.8, monochloroacetone and trichloromethane were formed, but 1, 1, 1-trichloroacetone was not detected. Therefore, it was concluded that the formation of monochloroacetone is a rate-limiting step in the reaction sequence at pH=7 and the amounts of trichloromethane depend on the concentration of OH- in the following equation. CH8COCCl3+OH-→CH3COO-+CHCl3
