send2suneet

Hi, Enthalpy means h = u + p.v When, we give heat dq to a closed system at constant pressure p then change in enthalpy dh = dq, where dq = du + p.dv but here only du remains in system, while p.dv is the part which is spended in doing work. Then "Why do we include p.dv in the enthalpy?" -------------------------------------------------- where--- h is enthalpy, u is Internal energy of the System, p is pressure of the system, v is Volume of the system --and system is of Closed Type.