## delta G

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

marcus lin 1E
Posts: 54
Joined: Fri Sep 28, 2018 12:28 am

### delta G

What does delta G represent?

Alexandra Albers 1D
Posts: 61
Joined: Fri Sep 28, 2018 12:18 am

### Re: delta G

Delta G represents the change in Gibbs Free Energy of a reaction, but if there is a knot symbol, then you are working with standard Gibbs Free Energy.

David S
Posts: 54
Joined: Fri Sep 28, 2018 12:15 am

### Re: delta G

Delta G, or the change in Gibbs free energy, represents the change in the max amount of energy available to do non-expansion work at a given Temp and Pressure. In other words $\Delta G = w_{max}$ @ const. T and P.

Exergonic processes have negative Delta G values, which corresponds to the release of energy that can be used to do work.
Endergonic processes have positive Delta G values, which corresponds to the consumption of energy that can be used to do work.

In biological systems, ATP hydrolysis is exergonic, releasing free energy that the cell can use to do work, such as the synthesizing of proteins, which is endergonic and absorbs the free energy released by ATP.

Diana Bibireata 1B
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Joined: Fri Sep 28, 2018 12:23 am

### Re: delta G

Delta G is the change in Gibbs free energy. The equation commonly used is: delta G = delta H - T(delta S). Gibbs free energy is also a state function.

Kevin Tang 4L
Posts: 83
Joined: Fri Sep 28, 2018 12:28 am

### Re: delta G

ΔG = ΔH - TΔS represents the change in Gibbs free energy. Spontaneous reactions are exergonic, when ΔG is less than 0, showing a release in free energy. Reactions that are not spontaneous, on the other hand, are endergonic when ΔG is greater than 0.

Anjali_Kumar1F
Posts: 62
Joined: Fri Sep 28, 2018 12:25 am

### Re: delta G

How is a photosynthesis reaction exergonic?