Moderators: Chem_Mod, Chem_Admin

Posts: 63
Joined: Fri Sep 28, 2018 12:16 am


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
Posts: 52
Joined: Fri Sep 28, 2018 12:17 am

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

Posts: 60
Joined: Fri Apr 06, 2018 11:03 am

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.
Unknown.png (6.39 KiB) Viewed 82 times

Return to “Gibbs Free Energy Concepts and Calculations”

Who is online

Users browsing this forum: No registered users and 3 guests