What is Enthalpy?
The following video does go further than you need, but gives a good explanation:
Enthalpy of Formation
Enthalpy of Formation values can be very useful for calculating the enthalpy change in a reaction. There are two ways to do this:
- Find the sum of the enthalpies of formation of the products.
- Find the sum of the enthalpies of formation of the reactants.
- Subtract the latter from the former.
- Write out the equations that each enthalpy of formation represents
- Use Hess' Law