A. Morgenstern et H. Oppermann, INVESTIGATION ON THE THERMAL-DECOMPOSITIO N OF AMMONIUM HALIDES, Zeitschrift fur Naturforschung. B, A journal of chemical sciences, 52(6), 1997, pp. 696-706
The decomposition equilibria of Ammonium Lanthanum Halides (NH4)(2)LaX
5 were determined by total pressure measurements in a membrane zero ma
nometer. The phases (NH4)(2)LaX5 decompose in one step to give solid L
aX3 and gaseous NH3 and HX. From the decomposition functions the entha
lpies of formation and the standard entropies of the phases are derive
d. Delta H-B degrees(NH4)(2)LaCl5,f,298) = -411,7 +/- 2,2 kcal/mol; S
degrees((NH4)(2)LaCl5,f,298) = 86,7 +/- 2,3 cal/Kmol; Delta H-B degree
s(NH4)(2)LaBr5,f,298) = -351,6 +/- 3,5 kcal/mol; S degrees((NH4)(2)LaB
r5,f,298) = 101,1 +/- 1,8 cal/Kmol; Delta H-B degrees(NH4)(2)LaI5,f,29
8) = -268,91 +/- 3,9 kcal/mol; S degrees((NH4)(2)LaI5,f,298) = 115,5 /- 4,3 cal/Kmol.