### Value of G

Posted:

**Sat Feb 03, 2018 5:21 pm**What is the lowest value that G can be? 0?

Created by Dr. Laurence Lavelle

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

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=135&t=26793

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Posted: **Sat Feb 03, 2018 5:21 pm**

What is the lowest value that G can be? 0?

Posted: **Sat Feb 03, 2018 5:32 pm**

I don't think there is a lowest value that G can be. And in many instances G is negative. If you look at the table of Gibbs Free Energy of formation in the back of the textbook, many of the values are below 0.

Posted: **Sat Feb 03, 2018 5:33 pm**

I am not sure exactly on the lowest value of G, but I do know that delta G can have a positive value, negative value, and a value of 0 because it is a state function so you have to think about final minus initial.

Posted: **Sat Feb 03, 2018 5:58 pm**

Yes, I'm not sure if G can have a lowest value, but if I'm remembering correctly, Lavelle said that measuring G alone is very difficult, therefore we always measure the change in G. If you meant to ask about DeltaG, DeltaG can't have a lowest value, and if it does, then it definitely wouldn't be 0! Remember, if DeltaG is positive, then it is an endergonic reaction that requires energy, and if DeltaG is negative, then it is an exergonic reaction that releases energy. This point alone proves that the "lowest" value for DeltaG cannot be 0! Hope this helps! (:

Posted: **Sun Feb 04, 2018 1:24 pm**

What exactly is G, and how does it differ from delta G in terms of what we use it for?