4. Calculate the standard enthalphy change (AH") for the following reaction: H2(g) + I2(g) 2 HI(g) Using (a) bond dissociation energies (H-H : 436.4 kJ/mol; I-I : 151.0 kJ/mol; H-I : 298.3 kJ/mol) (b) standart enthalphy of formations for reactants and products (AH; for I2(g) : 61.0 kJ/mol; AH, for HI(g) : 25.9 kJ/mol)