Abstrakt

Thermodynamics of the Solvation of Lead Nitrate in Mixed Propanol-H2O Solvents at Different Temperature

Esam A Gomaa and Elsayed M Abou Elleef, Ahmed Fekri, Mohamed Khairy and Reham M Abou Karn

The aim of this study was to determine the thermodynamics of the solvation of Pb(NO3)2in mixed propanol-H2O solvents , which is very toxic heavy metal salt at different temperatures. The Gibbs free energies as very important thermodynamic property were evaluated for Pb(NO3)2 in mixed propanol-H2O solvents at different temperature from the experimental solubility measurements. The ratio of the ionic radii between lead and nitrate ions was used to divide the total Gibbs free energy of the salt into its individual contribution in the mixtures used. Libration Gibbs free energy associated with the moving Pb(NO3)2 in standard gas state to standard state in solution was evaluated according to specific cycle for the solvation process using the solubility product. Also the lattice energy for Pb(NO3)2(cr) was also calculated and used for further evaluation (the symbol (cr) denotes the crystalline phase). The conventional Gibbs free energies for the cation (Pb2+) and anion (NO3-) were estimated theoretically and also the Gibbs free energy of NO3- gas was evaluated and all values were discussed.