Gibbs Free Energy

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Gibbs Free Energy

Postby eduardomorales5 » Wed Feb 19, 2020 4:21 pm

If the Gibbs free energy value is positive, does it also imply that the reaction is endothermic? Or could the reaction also be exothermic?

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Re: Gibbs Free Energy

Postby 005391550 » Wed Feb 19, 2020 4:57 pm

if the change in gibbs free energy is positive, it does not necessarily mean that delta H (enthalpy) is positive or negative because it also takes into account temperature and entropy. a reaction is endothermic if delta H is positive and exothermic if delta H is negative.

Justin Quan 4I
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Re: Gibbs Free Energy

Postby Justin Quan 4I » Wed Feb 19, 2020 6:53 pm

To add on, if ∆G is positive, then the forward reaction is non-spontaneous. Whether or not a reaction is endothermic or exothermic is dependent on ∆H. If you were giving ∆G & ∆S, then you can use the equation ∆G = ∆H - T∆S to predict if the reaction is endothermic or exothermic. However, just knowing ∆G alone does not imply anything about ∆H.

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