Thermodynamic is the branch of chemistry which deals with heat as we will as energy of system as we will as change in the energy of system. The increasing amount of the heat of system also increases the energy of system. So, thermodynamic includes the study of energy change of system. The movement of heat from one system to other takes places because of difference in temperature. The flow of heat as we will as also energy doesn’t take place in case of identical systems with equal value of temperatures. Some useful thermodynamic terms are enthalpy, internal energy, as we will as entropy. Here, we discuss about enthalpy of system as we will as the change in enthalpy of system. The enthalpy of system is similar to the internal energy of system which is the total energy of system however it’s equal to amount of absorbed or released hat of system at constant pressure. The enthalpy change is similar to change in internal energy of system. It’s denoted with the symbol of H. let’s discuss about this thermodynamic term.