enthalpy, entropy, Gibbs Free Energy signs






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Deepika Pugalenthi 1A
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

enthalpy, entropy, Gibbs Free Energy signs

Postby Deepika Pugalenthi 1A » Fri Feb 15, 2019 12:22 pm

For what signs of enthalpy, entropy, and Gibbs Free Energy is a reaction spontaneous and when is it not spontaneous?

Helen Zhao 1F
Posts: 31
Joined: Fri Sep 28, 2018 12:20 am

Re: enthalpy, entropy, Gibbs Free Energy signs

Postby Helen Zhao 1F » Fri Feb 15, 2019 12:45 pm

In a spontaneous reaction, enthalpy is negative, entropy is positive and Gibbs Free Energy is negative. In a nonspontaneous reaction, enthalpy is positive, entropy is negative and Gibbs Free Energy is positive.

Patrick Cai 1L
Posts: 93
Joined: Fri Sep 28, 2018 12:25 am

Re: enthalpy, entropy, Gibbs Free Energy signs

Postby Patrick Cai 1L » Fri Feb 15, 2019 1:07 pm

There are two other cases where temperature has to be considered. If enthalpy is positive but entropy is also positive, at high temperatures the reaction would have a negative change in free energy and is spontaneous; if enthalpy is negative but entropy is also negative, at low temperatures the reaction would have a negative change in free energy and is also spontaneous.

LedaKnowles2E
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

Re: enthalpy, entropy, Gibbs Free Energy signs

Postby LedaKnowles2E » Fri Feb 15, 2019 1:28 pm

When Gibbs free energy is negative the process is spontaneous.


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