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Postby CaminaB_1D » Sun Feb 24, 2019 1:29 am

I do not completely understand how the values of enthalpy and entropy explain the spontaneity of a reaction (aka the concepts of the Gibbs free energy equation), can someone give me a quick run down?

Elias Omar 1G
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Re: Concepts

Postby Elias Omar 1G » Sun Feb 24, 2019 2:29 am

Gibbs Free Energy is what really determines spontaneity:
If ∆G is negative then the reaction is spontaneous. If it's positive the reaction is non-spontaneous.
Here's how to relate entropy and enthalpy to spontaneity:
∆G positive, ∆ H negative - Spontaneous at all temperatures
∆G positive, ∆H positive - Spontaneous at high temperatures
∆G negative, ∆ H negative - Spontaneous at low temperatures
∆G negative, ∆ H positive - Process not spontaneous at any temperature, however reverse process is spontaneous at all temperatures

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Re: Concepts

Postby Nandhini_2K » Sun Feb 24, 2019 3:23 am

If delta G is negative: favors products and spontaneous in forward rxn.
If delta G is positive: favors reactants and non-spontaneous in forward rxn.
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