Answer:
ΔH∘f = 175Kj
Explanation:
Heat of Formation (ΔH∘f) is the amount of energy required or the amount of heat liberated or absorbed when 1mol of substance is formed as represented i a balanced chemical equation.
ΔH∘f = (2ΔHc + 2ΔHD) - (2ΔHA + ΔHB)
ΔH∘f = (2x175 + 2x(-521)) - (2x(-227) +(-413))
ΔH∘f = 350 - 1042 - (-454 -413)
ΔH∘f = -692 + 867
ΔH∘f = 175Kj