The investigation of thermodynamic parameters of kinetic reaction between o-phenylenediamine and gold (III)

ALTUN Ö., AKBAŞ H.

Journal of Chemical Thermodynamics, cilt.39, sa.11, ss.1413-1417, 2007 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 39 Sayı: 11
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1016/j.jct.2007.03.019
  • Dergi Adı: Journal of Chemical Thermodynamics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1413-1417
  • Anahtar Kelimeler: Gold (III), o-Phenylenediamine, Reaction kinetic, Spectrophotometry, Thermodynamic parameters
  • Trakya Üniversitesi Adresli: Evet

Özet

A visible spectrophotometric method has been developed for the reaction kinetics of o-phenylenediamine in the presence of gold (III). The method is based on the measurement of the absorbance of the reaction o-phenylenediamine and gold (III). Optimum conditions for the reaction were established as pH 6 at λ = 466 nm. When the reaction kinetic of o-phenylenediamine by gold (III) was investigated, it was observed that the following rate formula was found as ln (A/A0) = -kt, according to absorbance measurements. The activation energy Ea and Arrhenius constant A were calculated from the Arrhenius equation as 1.009 kJ · mol-1 and 3.46 · 10-2 s-1, respectively. Other activation thermodynamic parameters, entropy, ΔS (J · mol-1 · K-1), enthalpy, ΔH (kJ · mol-1), Gibbs free energy, ΔG (kJ · mol-1) and equilibrium constant, Ke were calculated at T = (283.2, 303.2, 323.2, and 343.2) K. The study was exothermic due to the decrease of entropy and was a non-spontaneous process during activation. © 2007.