Thermodynamics of dilute solutions of silver halides in molten potassium nitrate-barium nitrate

Abstract

Potentiometric titrations of dilute solutions of silver nitrate in molten KNO 3Ba(NO 3) 2 with potassium halides have been carried out. The solubility products of AgCl, AgBr and AgI in this solvent at 350° were found to be (7·91 ± 0·35) × 10 −5, (4·023 ± 0·23) × 10 −6 and (1·964 ± 0·39) × 10 −8 (mole/1000 g) 2 respectively. Heats and free energies of solution for the above halides were 19·15, 24·05, 32·83 ± 0·5 and 16·96, 20·65, 27·25 ± 2·5 Kcal/mole respectively; these have also been estimated from available thermal and thermodynamic data by the application of the FFG cycle. The agreement between experimental and the estimated values is fairly good. This shows the potentiality of such calculations in making predictions, a priori, of the above parameters in reciprocal molten salt systems of the type Ag +, K +, Ba 2+/X −, NO 3 −.