### Spontaneous Reactions and Relation to Delta G°

Posted:

**Sun Feb 04, 2018 8:18 pm**If a reaction is spontaneous, why does that imply that Delta G°of the reaction is positive?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=135&t=26878

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Posted: **Sun Feb 04, 2018 8:18 pm**

If a reaction is spontaneous, why does that imply that Delta G°of the reaction is positive?

Posted: **Sun Feb 04, 2018 8:24 pm**

Delta G is negative for spontaneous reactions.

If you see the equation for delta G: delta G(system)=delta H(system)-T*delta S

The sign for delta G is the opposite for delta S of the system

And since delta S has to be positive for spontaneous, delta G is negative.

If you see the equation for delta G: delta G(system)=delta H(system)-T*delta S

The sign for delta G is the opposite for delta S of the system

And since delta S has to be positive for spontaneous, delta G is negative.