Part A: For which of the following reactions is ΔH∘rxn equal toΔH∘f of the product(s)? You do not need to look up any values toanswer this question.
2Li(s)+F2(g)→2LiF(s)
S(s)+O2(g)→SO2(g)
Li(s)+12F2(g)→LiF(s)
SO(g)+12O2(g)→SO2(g)
SO3(g)→12O2(g)+SO2(g)
Li(s)+12F2(l)→LiF(s)
Part B: The combustion of propane, C3H8, occurs via thereaction
C3H8(g)+5O2(g)→3CO2(g)+4H2O(g)
with heat of formation values given by the following table:
| Substance | ΔH∘f
(kJ/mol) |
| C3H8 (g) | -104.7 |
| CO2(g) | −393.5 |
| H2O(g) | −241.8 |
Calculate the enthalpy for the combustion of 1 mole ofpropane.
