ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 21, Number 4
JKCSEZ 21(4)
August 20, 1977 

The reaction of phenylhydrazine with bromine in sulfuric acid solution has been studied kinetically. The pseudo-second-order rate constant is approximately inversely proportional to hydrogen-ion concentration when the concentration of sulfuric acid is lower than 1M. arom the study of the effect of potassium bromide concentration on the rate constant, it is concluded that both neutral bromine and tribromide ion participate in the reaction, the rate constants in 0.01M H2SO4 being 5 × 105M-1·sec-1 and 0. 7 × 105M-1·sec-1, respectively at 20℃. The pseudo-second-order rate constant of 2.4-dinitrophenylhydrazine-bromine reaction is independent of hydrogen ion concentration. From the KBr addition experiment, the rate constants for Br2 and Br3- were obtained as 1.2 × 105M-1·sec-1 and 2.0 × 104M-1·sec-1, respectively.