## deltaG at equilibrium

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

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

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

jillian1k
Posts: 54
Joined: Sat Jul 22, 2017 3:00 am

### deltaG at equilibrium

I know Dr. Lavelle said most of the time we'll be working with systems at equilibrium, but how will we know when a system is not at equilibrium unless it's stated? Would being given the boiling point of the system be one indicator of equilibrium always (since it's where the liquid and gas phase coexist)?

Cynthia Tsang
Posts: 52
Joined: Fri Sep 29, 2017 7:07 am
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### Re: deltaG at equilibrium

deltaG = 0 at equilibrium, so that might be an indicator, but I'm not sure if that would be given.

Christine Wastila 1H
Posts: 61
Joined: Fri Sep 29, 2017 7:04 am

### Re: deltaG at equilibrium

If given concentration or pressure, you could calculate Q and compare it to K if that value is given.

sahiltelang-Discussion 1J
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

### Re: deltaG at equilibrium

Another thing that we can look at to determine this is by looking at the deltaG of the products vs the reactants. When both of these two values equal each other then we know that the reaction is at equilibirum. If not then we can calculate the reaction quotient and see how the reaction will proceed

Michael Cheng 1C
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Joined: Thu Jul 13, 2017 3:00 am

### Re: deltaG at equilibrium

How will you know using the Gibbs Free energy which way the reaction will proceed if its not at equilibrium?

Sarah Maraach 2K
Posts: 31
Joined: Thu Jul 27, 2017 3:00 am

### Re: deltaG at equilibrium

Calculating a negative deltaG means that the reaction is favorable in the forward direction. However, if you get a positive deltaG, this means the current direction is unfavorable, so it would proceed in the reverse direction.