Hey, so I'm currently going into A2 and since energetics was a topic I really struggled with last year I'm going over it again...and I've completely forgotten Hess' Law.
I keep trying to do equations but I can never get them the right way around - is there one equation i can just use for combustion and formation?
What I thought could work was this:
formation:
ΔH = ΔHproducts - ΔHreactants
combustion:
ΔH = ΔHreactants - ΔHproducts
But I've been told I have to make a new equation every time?
Also, if the question gives you the enthalpies of formation but asks for the enthalpy of combustion, do you use the formation equation?