The enthalpy change for the oxidation of styrene Cs Hs is me

The enthalpy change for the oxidation of styrene, Cs Hs, is measured by calorimetry. C8Hs() + 10 O2(g) 8 CO2 (g) + 4 H2O(1) r H ,--4395.0 kJ/mol-rxn Use this value, along with the standard enthalpies of formation of CO2 g and H2O CO2(g) and H2O() are -393.509 kJ/mol and -285.83 kJ/mol respectively to calculate the enthalpy of formation of styrene n klmo. , for Enthalpy of formation = kJ/mol

Solution

Given:
Ho rxn = -4395.0 KJ/mol
Hof(O2(g)) = 0.0 KJ/mol
Hof(CO2(g)) = -393.509 KJ/mol
Hof(H2O(l)) = -285.83 KJ/mol

Balanced chemical equation is:
C8H8(l) + 10 O2(g) ---> 8 CO2(g) + 4 H2O(l)

Ho rxn = 8*Hof(CO2(g)) + 4*Hof(H2O(l)) - 1*Hof( C8H8(l)) - 10*Hof(O2(g))
-4395.0 = 8*(-393.509) + 4*(-285.83) - 1*Hof(C8H8(l)) - 10*(0.0)
Hof(C8H8(l)) = 103.608 KJ/mol
Answer: 103.608 KJ/mol