Enthalpy

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904475052_
Posts: 27
Joined: Fri Sep 25, 2015 3:00 am

Enthalpy

Postby 904475052_ » Wed Jan 06, 2016 4:30 pm

Why exactly is enthalpy a state property?

Ronald Yang 2F
Posts: 86
Joined: Fri Sep 25, 2015 3:00 am

Re: Enthalpy

Postby Ronald Yang 2F » Wed Jan 06, 2016 5:01 pm

Enthalpy is a state function because it's value is determined solely by it's current state. It is not dependent on the path taken to reach that state, as enthalpy is dependent only on the initial and final conditions, which is why we usually compute ΔH. However, for something like heat, it's value is dependent on the path, as it refers to a "transfer" in energy, and so, the process with which heat is transferred affects the value of heat. Only through this "path" can heat exist. Enthalpy can exist at specific points in a "path," so the path is negligible.

Jacqueline Lee
Posts: 21
Joined: Fri Sep 25, 2015 3:00 am

Re: Enthalpy

Postby Jacqueline Lee » Wed Jan 06, 2016 5:15 pm

Enthalpy is a state property because its value is not dependent on the path taken to obtain that state.
The best way that I can think of to describe it would be to look at this graph

https://upload.wikimedia.org/wikipedia/commons/thumb/2/24/Activation_energy.svg/360px-Activation_energy.svg.png

The energy difference between the reactants and products will remain the same whether or not a catalyst was used in the reaction(the different paths).

904475052_
Posts: 27
Joined: Fri Sep 25, 2015 3:00 am

Re: Enthalpy

Postby 904475052_ » Thu Jan 07, 2016 8:56 pm

thanks!


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