To calculate the ΔH°rxn using bond energies, we’re going to use the following equation:
Let’s first figure out what kind of bonds and how many moles are present in each reactant and products because the given bond energies are per mole.
Balanced Reaction: H2(g) + I2(g) → 2 HI(g)
*always make sure that the given reaction is balanced
From the bond energies given below, estimate the ΔH° for the reaction:
H2(g) + I2(g) → 2HI(g)
Bond energies (kJ/mol):
H–H = 436
H–I = 297
I–I = 151
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