Given the following two thermochemical equations, H2(g) + ICI(8) HCl(g) + HI(g) AH° = -83.1 kJ = 12(8) + HCl(g) HI(g) + ICI(8) AH° = 73.6 kJ determine the standard enthalpy change associated with the following reaction: H2(g) + 21C1(g) 2HCl(g) + 12(9) AH° = ? -9.5 kJ -283.0 kJ O 156.7 kJ 0 -156.7 kJ O 9.5 kJ