My chemistry teacher said that H (enthalpy) alone has no physical significance it is ∆H or change in enthalpy that has a physical significance. But my book says that both have a significance and H alone represents the total heat content of the body. Thus I am in a confusion, please help me.


1 Answer 1


Offcourse H and ∆H have physical significance. H represents the enthalpy of a system. Enthalpy refers to the sum of the internal energy of a system plus the product of the system's pressure and volume.

The ∆ symbol is used to represent change. Therefore, ∆H represents the change in enthalpy of a system in the reaction. So your book is completely correct.

  • 4
    $\begingroup$ That being said, the teacher is right too (in a way). We pretty much never know absolute enthalpy of anything. Arguably, it may not even be well-defined. $\endgroup$ Commented Mar 22, 2017 at 18:04
  • $\begingroup$ @IvanNeretin I completely agree with your point. $\endgroup$
    – jyoti proy
    Commented Mar 22, 2017 at 18:12
  • $\begingroup$ @IvanNeretin Ya thats true. Agreed with you $\endgroup$
    – Yb609
    Commented Mar 22, 2017 at 18:13

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