Question

What is enthalpy ? .....

Answer 1

Enthalpy. ... When a substance changes at constant pressure, enthalpy tells how much heat and work was added or removed from the substance. Enthalpy is similar to energy, but not the same. When a substance grows or shrinks, energy is used up or released

Answer 2

$\huge\textbf{Enthalpy :}$



It is the amount of heat energy possessed by a system.


It is the sum of internal energy and product of pressure and volume of a system.

i.e.

H = U + PV



It's unit is J or KJ per mol.



Enthalpy change is represented by ∆H

i.e.

∆H = ∆U +P∆V


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