Calculate the delta H for ethylene glycol?

Question

2(CH2OH)2 (l) + 5 O2 (g) > 4 CO2 (g) + 6 H2O (l)

The standered heat of combustion for ethylene glycol is -2356 KJ/mol.
CO2 (g) = -393.5 KJ/mol
H20 (l) = - 285.58 KJ/mol

Answer 1

To solve this kind of problem, you need to know that DeltaH for a reaction is equal to the sum of the DH of formation for the products - the sum of DH of formation of the reactants.. So you can set up the equation to solve as:

-2356 kJ = 4(-393.5 kJ) + 6(-285.58 kJ) -2(DH)

If you solve this for DH (the enthalpy of formation of ethylene glycol) you'll have your answer.