Question

The homework question is :
Calculate the Delta H for the following reaction:

C6H6 + O2 -> C + H2O(l)

State whether the reaction is exothermic or endothermic.

I'm not sure where to go with this but so far I balanced out the formula to this

C6H6 + (3/2)O2 -> 6C2 + 3H2O

I found online that the standard enthalpy of formation of C6H6 is 48.95 kJ/mol but where do I go from there?

Answer 1

Is that the equation given for the reaction? USUALLY the products are CO2 and H2O. At any rate, here is what you do.
Yes, balance the equation. Then
dHrxn = (n*dHf procuts) - (n*dHf reactants)
Look up the dHf in your text or notes. Lots of places on the net also. By the way, for C I would not write it as C2 AND you will need to know if it is graphite or not.
dHrxn is - it is exothermic; if + endothermic.

Answer 2

I think it is an error. Usually we have to get CO2 instead of C as it is a combustion reaction and in theory it is an exothermic reaction