Enthalpy

This is defined as heat flow under constant pressure. Enthalpy is a state function too which means it only depends on the initial/beginning and final states. The variable H represents enthalpy.

• The sign of ∆H is very important and can be used to identify what is happening to the energy.
  • ∆H > 0 (positive) means energy is absorbed during the reaction. This signals that the process is endothermic.
  • ∆H < 0 (negative) means energy is evolved (released) during the reaction. This shows the process is exothermic.