Abstract

Calorimetric determination of the neutralization of tham-HCl from 00C to 500C using a new isothermal calorimeter connected to an automated temperature transducer

Author(s): J.C.Moreno-Piraj�?�?�?�?�?�?�?¡n, L.Giraldo-Guti�?�?�?�?�?�?�?©rrez

At our laboratory, we developed a new cell type for the batch isothermal calorimetry of dissolution enthalpies to determine small amounts of easily soluble or slightly soluble solids. An innovative mixing system aimed at minimizing errors related to the common brittle point breakage effect has been coupled with a pneumatic valve, thus allowing it to work as a cell within an environment involving automatic information management done with software and electronics. The calorimetric cell has a capacity of 20 mL and the sample valve can handle solid samples between 5.0 and 30.0 mg. The experimental conditions suggested in specialized literature were maintained. Values of -H° of 33.41340.0005, 32.1248 0.0012, 30.7357 0.0014, 30.2754  0.0017, 30.2691  0.0007, 29.33950. 0023, 28.7232  0.0032 and 26.0705  0.0028Kjoul./mole at 0, 10, 10, 15, 20, 25, 30, 40, and 50°C, respectively, are reported. The results of the study are then compared with existing studies in calorimetrics, and confirmthe results of the standard THAMHCl calorimetric system.