The standard enthalpies of formation of crystalline aluminium(III) bromide and aluminium(III) iodide

Article abstract of DOI:10.1016/S0021-9614(80)80007-3

The enthalpies of solution of crystalline AlCl3 and KBr were measured successively in one portion of 3.5 mol dm^-3 HCl solution as well as AlBr3 and KCl in another.The measurements were carried out in a 100 cm³ reaction vessel of the isoperibol calorimeter LKB-8700.The standard enthalpy of the resuming reaction: AlCl3(c) + 3 KBr(c) = AlBr3(c) + 3 KCl(c), was found to be ΔH⁰_r(298.15 K) = (63.4 +/- 1.3) kJ mol^-1 which leads to ΔH⁰_f(AlBr3, c, 298.15 K) = (-512.6 +/- 1.9) kJ mol^-1.The same measurements were carried out for AlCl3 and KI and for AlI3 and KCl.The standard enthalpy of reaction: AlCl3(c) + 3 KI(c) = AlI3(c) + 3 KCl(c), was found to be ΔH⁰_r(298.15 K) = (80.1 +/- 1.4) kJ mol^-1 which leads to ΔH⁰_f(AlI3, c, 298.15 K) = (-302.9 +/- 2.0) kJ mol^-1.