Thermodynamics of the Titanium Chlorides. I. Heat of Formation of Titanium Trichloride

Abstract

The heat of formation of titanium trichloride has been determined by measuring the heats of solution of TiCh(l) and TiCl3-(s) in a solvent of HCl-FeCl3 in an ice calorimeter. The heat of formation of the trichloride is based upon the heat of formation for TiCl4(l) of -192.1 ± 0.6 kcal./mole. The value obtained for the heat of formation of TiCl3(s) at 298°K. is -172.2 ± 0.7 kcal./mole. THERMODYNAMICSOF THE TITANIUM CHLORIDES. II. HEAT OF FORMATION OF TITANIUM DICHLORIDE1

Heat of formation of titanium trichloride

“…The value obtained in this investigation is essentially the same as that obtained by Clifton and MacWood [ 1 ] from measurements of the energies evolved when TiCl 3 (c) and TiCl 4 (liq) were dissolved in an aqueous solution of HC1 and FeCl 3 .…”

“…Several independent determinations of the heat of formation of titanium trichloride have been reported during the past few years [ 1 , 2 , 3 , 4 , 5 , 6 ]. 1 The only values previously available were those estimated by Brewer, Bromley, Gilles, and Lofgren [ 7 ] and by Kubaschewski and Evans [ 8 ], which are now generally known to be low.…”

“…The difference between the heats of formation of TiCl 4 and TiCl 3 may be determined from a combination of the heat of oxidation and hydrolysis of TiCl 3 with the heat of hydrolysis of TiCl 4 and with certain auxiliary data. This method is similar to that employed by Clifton and MacWood [ 1 ], except that the experiments were performed at 30 °C instead of 0 °C and iodine was used as the oxidizing agent instead of FeCl 3 .…”