Abstract: The controlled "potential coulometry is suitable for examining the effects of slower reactions coupled to the electron transfer process such as in sulfur-DMSOsystem, since the time window of this method is longer. The theorietical treatment for the first step of sulfur reduction was completed, while the working curve of T_1/2 -lgr that allowst he determination of apparent rate constant for reaction S₈^2-= S₆^2-+ (1/4)S₈ with a value of k=6×10^-3s^-1 was given. In the second step of sulfur reduction, the electrolysis curve with almost a horizontal at begining and a wave shape at some later were found. The experimental phenomena were explained on the base of results obtained previously.

Key words: Reduction of sulfur, Coulometry, Organic medium