‘Enthalpy Titrations’ and Thermochemistry in Molten Salts

Abstract

AUTOMATIC instrumentation for recording ‘thermometric titration’ curves has been described in recent papers^1,2 from these laboratories, which represent the first report of a continuous titration procedure successfully carried out in a molten salt solvent. This approach is capable of yielding a wealth of quantitative information on the chemistry of fused salts. Significant thermochemical results, involving the precipitation of silver halides and of silver chromate, are summarized in this communication. A typical titration curve (of chromate with silver), obtained under essentially adiabatic conditions, is illustrated in Fig. 1. Methodologically this is a differential thermometric titration curve, because temperature has been recorded as a function of the amount of titrant. From a phenomenological point of view, however, Fig. 1 represents an ‘enthalpy titration’, the shape of the curve reflecting the heat evolved in the reaction as a function of added silver.