0.8 Nitric acid hydrates have received much attention as possible catalysts for heterogeneous reactions that bring about the Antarctic ozone hole. Worsnop et al. investigated the thermodynamic stability of these hydrates under conditions typical of the polar winter stratosphere (Science 259, 71 (1993).). They report thermodynamic data for the sublimation of mono-, di-, and trihydrates to nitric acid and water vapours, HNO3-NH2O(s) HNO3(g) + nH2O(g), for n = 1, 2, and 3. Given AG and AH" for these reactions at 220 K (see table below), use the Gibbs- Helmholtz equation to compute A,Gat 190 K. (Hint: integrate the Gibbs-Helmoltz equation within the temperature interval) n 4,6/(kJ mol') A,H"/(kJ mol"') 1 42.6 127 2 69.4 188 3 93.2 237