Summary:
- Enthalpy is the heat content of a system at constant pressure.
- It is determined by the energies needed to break chemical bonds and to form chemical bonds.
- Enthalpy is an extensive property, determined in part by the amount of material we work with.
- The state of reactants and products (solid, liquid, or gas) influences the enthalpy value for a system.
- The direction of the reaction affects the ent Halpy value.
- A reaction that takes place in the opposite direction has the same numerical entHalpy value but the opposite sign.