Signs for Gibbs Free Energy






Moderators: Chem_Mod, Chem_Admin

Abigail Menchaca_1H
Posts: 104
Joined: Sat Sep 07, 2019 12:19 am

Signs for Gibbs Free Energy

Postby Abigail Menchaca_1H » Sun Feb 16, 2020 11:34 pm

What does it mean when Gibbs Free Energy is negative or positive?

Prasanna Padmanabham 4I
Posts: 111
Joined: Thu Jul 25, 2019 12:17 am

Re: Signs for Gibbs Free Energy

Postby Prasanna Padmanabham 4I » Sun Feb 16, 2020 11:35 pm

When the Gibbs Free Energy is negative it means that the forward reaction is spontaneous while if it is positive, it means that the reverse reaction is spontaneous.

Kimberly Koo 2I
Posts: 99
Joined: Sat Aug 17, 2019 12:17 am

Re: Signs for Gibbs Free Energy

Postby Kimberly Koo 2I » Sun Feb 16, 2020 11:37 pm

If Gibbs free energy is negative, then the process is spontaneous in the forward direction. If the Gibbs free energy is positive, then the process is nonspontaneous in the forward direction and spontaneous in the reverse direction.

SVajragiri_1C
Posts: 115
Joined: Thu Jul 11, 2019 12:16 am

Re: Signs for Gibbs Free Energy

Postby SVajragiri_1C » Mon Feb 17, 2020 12:30 am

When G is negative, the reaction is spontaneous and thermodynamically stable, and if G is positive the reaction is non-spontaneous and thermodynamically unstable. You can calculate this using the equation G = H - TS.

Louise Lin 2B
Posts: 97
Joined: Sat Aug 17, 2019 12:15 am

Re: Signs for Gibbs Free Energy

Postby Louise Lin 2B » Mon Feb 17, 2020 3:24 pm

A negative deltaG means that the reaction is spontaneous, and usually exothermic. A positive delta G means that the reaction is nonspontaneous, and usually endothermic.

kausalya_1k
Posts: 50
Joined: Wed Nov 14, 2018 12:23 am

Re: Signs for Gibbs Free Energy

Postby kausalya_1k » Mon Feb 17, 2020 6:47 pm

When deltaG is less than 0 (negative) the forward reaction is spontaneous. When deltaG is positive, the reverse reaction is spontaneous. When deltaG=0, the system is at equilibrium.

Shail Avasthi 2C
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

Re: Signs for Gibbs Free Energy

Postby Shail Avasthi 2C » Tue Feb 18, 2020 10:39 am

When ΔG is positive, the reaction is non-spontaneous and requires an input of energy to proceed towards the products. When ΔG is negative, the reaction is spontaneous and releases energy as it proceeds towards the products.

Mariah
Posts: 104
Joined: Fri Aug 02, 2019 12:16 am

Re: Signs for Gibbs Free Energy

Postby Mariah » Tue Feb 18, 2020 11:47 am

Prasanna Padmanabham 4I wrote:When the Gibbs Free Energy is negative it means that the forward reaction is spontaneous while if it is positive, it means that the reverse reaction is spontaneous.


Spontaneous means that it will occur on its own correct?

Katie Bart 1I
Posts: 104
Joined: Sat Aug 24, 2019 12:16 am

Re: Signs for Gibbs Free Energy

Postby Katie Bart 1I » Tue Feb 18, 2020 11:55 am

It also helps me to think of the signs in terms of energy being absorbed and released.

Jasmine Fendi 1D
Posts: 108
Joined: Sat Aug 24, 2019 12:15 am

Re: Signs for Gibbs Free Energy

Postby Jasmine Fendi 1D » Tue Feb 18, 2020 2:28 pm

When the sign is negative, it means that the reaction is spontaneous. That is because the reaction would result in molecules being in their most stable state which would require less energy to maintain the bonds. As a result, the overall energy is negative because energy is being released. The same is for the opposite. When the sign is positive, the reaction is not spontaneous and therefore requires energy.

lauraxie2e
Posts: 108
Joined: Fri Aug 09, 2019 12:17 am

Re: Signs for Gibbs Free Energy

Postby lauraxie2e » Tue Feb 18, 2020 3:49 pm

negative is exothermic and positive is endothermic

Kallista McCarty 1C
Posts: 212
Joined: Wed Sep 18, 2019 12:18 am

Re: Signs for Gibbs Free Energy

Postby Kallista McCarty 1C » Tue Feb 18, 2020 5:39 pm

Negative is spontaneous (exothermic) and positive is not spontaneous (endothermic)


Return to “Gibbs Free Energy Concepts and Calculations”

Who is online

Users browsing this forum: No registered users and 1 guest