From the following Information, calculate the standard change of enthalpy for the combustion of coal. SHOW WORK AND BALANCED REACTION!!!

Compound DeltaHf (kj/mol)
Coal 0.0
Carbon dioxide -393.5
Water (l) -285.9
Oxygen 0.0

Write and balance the equation. Then

dHf rxn = (n*dHf products) - (n*dHf reactants).

C + O2 ==> CO2

I don't know what you use as the formula for coal if it isn't C. You know it is a mixture of bunches of stuff but has a high percentage of carbon. It may have some hydrocarbons but unless the problem tells you how much you don't know how many water molecules are produced. My best guess is that you are to write the equation as I've done above.