Summary:
- The standard heat of formation is the enthalpy change associated with the formation of one mole of a compound from its elements in their standard states.
- The standard state of an element is its state at 25°C and 101.3 kPa.
- For example, iron is a solid, bromine is a liquid, and oxygen is a gas under those conditions.
- The graphite form of solid carbon is its standard state with , while diamond is not.
- Some standard heats of formation are listed in Table below.