## Reversible?

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

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

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

Crystal Escobar 1F
Posts: 13
Joined: Fri Sep 25, 2015 3:00 am

### Reversible?

How do you know if a reaction is reversible rather than irreversible?

Chem_Mod
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### Re: Reversible?

A process can be called a reversible process if by reversing the changes made to the system, you can go back to the original state of the system. Otherwise it is an irreversible process.

For ex - You have a system in state -1 and you increase the pressure and go to state-2. Now if you decrease pressure by same amount, you should go back to state-1 if the process was reversible. (Which is never usually true)

704628249
Posts: 43
Joined: Fri Sep 25, 2015 3:00 am

### Re: Reversible?

Most of the time they state it in the question. If it is reversible, work is usually -nRTln(V2/V1). If it is not reversible, work is normally -PdV.

Stevie Wisz
Posts: 59
Joined: Fri Sep 25, 2015 3:00 am

### Re: Reversible?

In almost all cases they will indicate whether the process is reversible or irreversible. But, if not, know that reversible have infinitely small volume changes where as irreversible have fairly larger volume changes. Reversible have potential to shift back to their equilibrium conditions whereas irreversible cannot/don't. Maximum work is done with reversible because it is pushing against a greater external pressure force than the irreversible one. Hope this helps! Course reader helps with this too! :)