Study the effect of acidity function on the kinetic of the two complexes formation produced from the reaction of salicylic acid with two diazotized reagents.

Abstract

The spectrophotometric method was used to the kinetics study of the formation reactions for colored drug complexes derived from electron-donating salicylic acid drug with the two diazotized reagents of (para-nitro aniline) and (sulfanilic acid sodium salt) at the acidic functions (pH4.9, pH7.1 and pH9.3) that accept these electrons at different acidic media The optimal concentration ratios of the two drug complexes with the two reagents were (1:10) for (drug:reagent), respectively. Experimentally , the kinetics of the formation of each drug complex was studied under its optimum conditions and at the three pH levels. It was  proved that drug complex formation followed a pseudo first order kinetic with respect to drug. The obtained results were discussed with an appropriate explanation for each one.