Question

How do you calculate the `DeltaH` for the combustion of `C_2H_5OH`?

Answer 1

For a start you don't calculate it.

Explanation:

You want the enthalpy change for the following reaction:

`C_2H_5OH(l) +3O_2(g) rarr 2CO_2(g) + 3H_2O(l) +Delta`

This is NOT calculated, but measured. Of course, if you have certan parameters, i.e. `DeltaH""^@""_f` for the reactants and products (you have for ONE of the reactants, which?), you can do an enthalpy summation, but at present you cannot find the enthalpy parameters for the given reaction.