Kinetic and thermodynamic study of the behaviour of diphenylcarbazide in aqueous solution with pH.

In order to find out about the chemical behaviour of the diphenylcarbazide (DPCI) in water, kinetic and thermodynamic studies were carried out using UV-Vis spectrophotometry within the 0-12 pH range. The kinetic parameters and acidity constant were then determined, and the results show that a pseudo first order reaction rate was observed during hydroxilation, while the reaction rate was also observed to increase with the pH. The acidity constant obtained with the aid of SQUAD was pK(a)=10.718+/-0.027.