. What do you mean by Enthalpy (H)
When we deal certain process in open vessels (at constant pressure). It becomes essential to introduce in place of internal energy, a new thermodynamic function called heat enthalpy. This new function is denoted by H.
H = E + PV
Every substance has a definite value of enthalpy in a particular state. It is also a
state function like internal energy. The change in enthalpy accompanying a process can be determined as
Hence the change in enthalpy of the system delta H may be defined as the amount of heat absorbed at constant pressure.