Photometric-Potentiometric Evaluation of the Hydrolysis Constants of N-Bromo Compounds

Article abstract of DOI:10.1007/BF00799558

The equilibrium concentrations of all reaction products emerging from the hydrolysis of N-bromo compounds in the presence of bromide and thereby also the hydrolysis constants (K₁) have been calculated from the absorbance at 392.8 nm, the pH-value and the initial concentrations of the N-bromo compound and the bromide.The following compounds have been investigated: N-bromo-succinimide: K₁ = 2.2E-6, 1,3-dibromo-5,5-dimethylhydantoin: K₁ = 1.7E-5, N-bromoacetamide: K₁ = 1.8E-6, N-bromo-monochloroacetamide: 5.2E-6, N-bromo-dichloroacetamide: K₁ = 8.9E-6 and N-bromo-trichloroacetamide: K₁ = 1.8E-5.The precision of the method, which is mainly suited for weak hydrolizing N-bromocompounds (K₁<1E-4) are discussed and the overall error of the calculated values was found to be in the range of <*>5-12percent.The reactivities in aqueous solution of the most frequently used N-bromo compounds are compared by means of the calculated HOBr equilibrium concentrations.The differences to be expected on the basis of the latters are at concentrations >1E-5 mol/l rather great, while they can be neglected in very dilute solutions (