Disproportionation and Vapor Pressure of TiCl2

Abstract

The disproportionation and sublimation of TiCl₂(s) have been investigated by means of a molybdenum effusion cell in a temperature range of 800 to 900°K. Heats and entropies of reaction at the average temperature of 850°K were obtained for three reactions: $$\begin{array}{c}\text{(1)\hspace{0.17em}2}{\mathrm{TiCl}}_2\mathrm{(s)=}{\mathrm{TiCl}}_4\mathrm{(g)+}\mathrm{Ti}\text{;ΔH=49.5±1\hspace{0.17em}}\mathrm{kcal}\text{,ΔS=32.2±1\hspace{0.17em}}\mathrm{cal}{/}^{°}\mathrm{C}.\\ \text{(2)\hspace{0.17em}3}{\mathrm{TiCl}}_2\text{(s)=2}{\mathrm{TiCl}}_3\mathrm{(g)+}\mathrm{Ti}\text{;ΔH=87.2±1\hspace{0.17em}}\mathrm{kcal}\text{,ΔS=62.1±1\hspace{0.17em}}\mathrm{cal}{/}^{°}\mathrm{C}.\\ \text{(3)\hspace{0.17em}}{\mathrm{TiCl}}_2\mathrm{(s)=}{\mathrm{TiCl}}_2\text{(g);ΔH=46.8±1\hspace{0.17em}}\mathrm{kcal}/\mathrm{mole}\text{,ΔS=30.7±}\mathrm{cal}{/}^{°}\mathrm{C}/\mathrm{mole}.\end{array}$$ X‐ray diffraction patterns of mixtures of TiCl₂ and TiCl₃ gave no evidence of any appreciable solid solution.