Question

For the reaction below, ΔrH° = −3908.7 kJ mol−1. What is the standard enthalpy of formation of C7H8(l) in kJ mol-1?

C7H8(l) + 9 O2(g) ⟶ 7 CO2(g) + 4 H2O(l)

Data:
Substance Standard enthalpy of formation (in kJ mol−1)
CO2(g) −393.5
H2O(l) −285.9

Answer 1

dHrxn = (n*dHo formation products) - (n*dHo formation reactants)
Substitute and solve for dHo formation C7H8(l).