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### Indications

Posted: Tue Feb 19, 2019 7:59 pm
Are there any characteristics of a reaction that would hint at the value of delta G being positive/negative or larger/smaller?

### Re: Indications

Posted: Tue Feb 19, 2019 8:08 pm
Since the equation to calculate for delta G is delta G = delta H - T(delta S), a small/negative delta H (enthalpy), large/positive T (temperature), and a large/positive S (entropy) would make for a very small/negative delta G.
The opposites would make delta G larger (more nonspontaneous).

### Re: Indications

Posted: Tue Feb 19, 2019 10:17 pm
If a reaction is spontaneous, then delta G is negative. A very negative change in enthalpy (exothermic reaction) will likely cause delta G to be negative. A very positive change in entropy would likely also make delta G negative. Like the previous comment said, the opposite would then make delta G more positive and not spontaneous.

### Re: Indications

Posted: Wed Feb 20, 2019 11:31 am
if you look in the txtbook there is a chart that does a good job of outlining this