September 15, 2019, 06:12:55 AM
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Topic: ∆G  (Read 400 times)

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Offline Hrushikesh

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∆G
« on: May 14, 2019, 10:08:49 PM »
∆G=∆H-T∆S
     =(∆E+∆PV)-T(q/T)
     =q+w+P∆V+V∆P-q
     =-P∆V+P∆V+V∆P
     =V∆P
!!!!! This means that at constant P and T ∆G is always zero.
Please tell me is this correct or not.
If not tell me where.

Offline mjc123

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Re: ∆G
« Reply #1 on: May 15, 2019, 04:36:05 AM »
The equations ΔE = q + w and ΔS = q/T apply only to a system that undergoes no chemical changes. Then it is no surprise that at constant P and T ΔG = 0, because G is a state function. If there is a reaction, you have to consider the energy and entropy changes between reactants and products.

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