Author/Authors :
Baluja، Sh. نويسنده Physical Chemistry Laboratory, Department of Chemistry, Saurashtra University, Rajkot-360005 (Gujarat), India Baluja, Sh. , Ramavat ، P. نويسنده Physical Chemistry Laboratory, Department of Chemistry, Saurashtra University, Rajkot-360005 (Gujarat), India Ramavat , P. , Nandha، K. نويسنده Physical Chemistry Laboratory, Department of Chemistry, Saurashtra University, Rajkot-360005 (Gujarat), India Nandha, K.
Abstract :
The acidity constants of some synthesized protonated pyrazolo quinazoline compounds were determined potentiometrically at ionic strength of 0.1 M in DMF: water (60:40 v/v) system at different temperatures (298.15 K to 318.15 K). The pKa values have been found to increase with increasing electron-donating nature of substitutions. Some thermodynamics parameters such as enthalpy (?H°), Gibb’s free energy (?G°) and entropy (?S°) of reactions have also been evaluated at different temperatures for these systems. The thermodynamic parameters indicate that dissociation process is not spontaneous and exothermic.
