Answer:
ΔH = 283kJ/mol
Explanation:
Using Hess's law, the ΔH of a reaction is equal to the sum of ΔH° of products times its coefficient subtracting the sum of ΔH° of reactants times its coefficient. Replacing, for the reaction:
ΔH = 2ΔH°C + 2ΔH°D - (2ΔH°A+ΔH°B)
ΔH = 2*193kJ/mol + 2*-493kJ/mol - (2*-235kJ/mol+ (-413kJ/mol)