POLAROGRAPHIC BEHAVIOUR OF SOME ACID DYES

Abstract

The polarographicbehaviour of three acid dyes Cfocein Orange G, Acid Alizarin Violet N and AcidOrange 10 in aqueous buffered solutions is represented. It is clear from the obtained results that the halfwavepotential shifts to more negative values as to be expected for processes that consume protons. Theresults indicate that the process of reduction is irreversible. The polarographicdiagrams of the studieddyes gives one difined irreversible wave. The interpretation of the polarographic reduction wave wasdiscussed. The diffusion coefficients of the three dyes were obtained. The aggregation constant in aqueoussolution has been calculated in terms of a monomer-dimer equilibrium.