Evaluation of Standard Changes in Enthalpy During Complex Formation of Mn(II), Ni(II), Cd(II) and Hg(II) with p-fluorobenzoylthioacetophenone

Abstract

The stability constant values of the complexes of p-fluorobenzoylthioacetophenone with bivalent manganese, nickel, cadmium and mercury at different temperatures viz. 283K, 293K and 303K have been determined using Calvin-Bjerrum’s pH titration technique as adopted by Irving and Rossotti. Standard change in free energy at desired temperatures were evaluated with the help of data of overall stability constants using the thermodynamic expression, ΔG° = −2.303 RT Log β. The standard changes in enthalpy associated with the complex formation reactions were evaluated with the help of Isobar equation. The standard enthalpy change was also calculated by using Gibbs-Helmholtz equation. From values obtained, the standard changes in enthalpy associated with the above complex formation have been thoroughly discussed.