The influence of temperature, ph and the type of oxime isomer onthe stability constant values of some azo dyes formations betweenoximes and the diazotized sulfanilic acid salt

Abstract EN

The paper deals with studying the effect of experimental factors on the value of stability constant (K) of the dyes formed by the reactions of aromatic aldoximes as 2- hydroxy benzaldoxime, 2, 4-dhydroxy benzaldoxime and 2-hydroxy-1 naphthaldoxime with diazotized sulfanilic acid salt.

Experimentally the following three physical parameters are found to be effective on K as, temperature, pH and type of syn or anti isomer of oxime.

The study includes several topics, one of them is the thermodynamic of dye formation which prove such process is spontaneous and exothermic.

The calculated the rmodynmic quantities change have negative values of Gibbs free energy and heat of reaction.

They have range average values between 30.1-44.6 and 0.6-59.5 in units of kJ.mole-1 respectively, depending on the structure of the azo dye formation.

The entropy changes for the complex formation are also mentioned and discussed.

The reaction of azo dye formation is based on donor-acceptor mechanism.