Standard enthalpy of formation of aqueous titanyl chloride, TiOCl 2(aq), at T = 298.15 K

Abstract

Enthalpies of solution of TiCl 4(l) in aqueous perchloric acid have been measured in an isothermal calorimeter at T = 298.15 K at ionic strengths of (1.964, 3.002, and 4.062) mol · kg −1. These results were extrapolated to zero ionic strength using an extended Debye–Hückel equation, to yield the standard enthalpy of solution Δ sln H m ∘ ( T = 298.15 K ) = - ( 268.03 ± 0.45 ) kJ · mol - 1 ; from which the standard partial molar enthalpy of formation of the titanyl ion was derived: Δ f H m ∘ ( TiO 2 + , aq, T = 298.15 K ) = - ( 689.4 ± 4.3 ) kJ · mol - 1 .