Kinetics vs Thermodynamics

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Vanessa Romero-Campos 2B
Posts: 39
Joined: Fri Sep 25, 2015 3:00 am

Kinetics vs Thermodynamics

Postby Vanessa Romero-Campos 2B » Sun Feb 25, 2018 9:47 pm

Is there a relationship between Kinetics and Thermodynamics? If something is kinetically stable, is it thermodynamically unstable, stable or is there no relationship between both?

SitharaMenon2B
Posts: 50
Joined: Thu Jul 27, 2017 3:01 am

Re: Kinetics vs Thermodynamics

Postby SitharaMenon2B » Sun Feb 25, 2018 9:52 pm

thermodynamics only looks at the initial and final state, while kinetics is focused on the path taken. When something is thermodynamically unstable or stable it does not affect whether it will be kinetically stable or unstable. However, the thermodynamic stability and kinetic stability together determine how the reaction will proceed

Niyanta Joshi 1F
Posts: 30
Joined: Thu Jul 13, 2017 3:00 am

Re: Kinetics vs Thermodynamics

Postby Niyanta Joshi 1F » Sun Feb 25, 2018 9:55 pm

Kinetic stability deals with the rate of the reaction. The slower the reaction, greater the kinetic stability. Whereas thermodynamic stability will depend on whether the reaction is spontaneous or not.

Julia Campbell 2F
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Joined: Sat Jul 22, 2017 3:00 am

Re: Kinetics vs Thermodynamics

Postby Julia Campbell 2F » Mon Feb 26, 2018 8:33 pm

Kinetics deals with the rate of a reaction and thermodynamics deals with whether the reaction is favorable or not.

A kinetically controlled reaction is one that does not occur because of a large activation energy barrier even though the products have a lower standard Gibbs free energy (i.e., the reaction is favorable because the product or products are more stable).

A well known example is diamond changing to graphite, which does not occur under ambient conditions even though graphite is thermodynamically more stable than diamond.

- Lavelle from 2014

andrewr2H
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Joined: Fri Sep 29, 2017 7:05 am

Re: Kinetics vs Thermodynamics

Postby andrewr2H » Mon Feb 26, 2018 9:05 pm

My understanding is that if a reaction is thermodynamically unfavorable, it cannot be kinetically favorable. And if a reaction is kinetically favorable, it must be thermodynamically favorable. However, a reaction being thermodynamically favorable does not automatically make it kinetically favorable.

Sarah 2F
Posts: 33
Joined: Fri Sep 29, 2017 7:06 am

Re: Kinetics vs Thermodynamics

Postby Sarah 2F » Thu Mar 01, 2018 4:49 pm

Kinetics is about the journey there and Thermodynamics is only about the beginning and end products.

Michael Cheng 1C
Posts: 51
Joined: Thu Jul 13, 2017 3:00 am

Re: Kinetics vs Thermodynamics

Postby Michael Cheng 1C » Sat Mar 03, 2018 10:10 pm

If a reaction is thermodynamically stable, will it automatically be kinetically stable?

Sirajbir Sodhi 2K
Posts: 47
Joined: Sat Jul 22, 2017 3:00 am

Re: Kinetics vs Thermodynamics

Postby Sirajbir Sodhi 2K » Sat Mar 03, 2018 11:34 pm

A system is thermodynamically stable depending on its thermodynamic potential energy (Gibb's, internal energy, enthalpy). Just because a reaction is thermodynamically stable, though, does not say anything about kinetic stability (that has to do with mainly activation energy and pre-equilibrium conditions). The graphite to diamond example is a good one to demonstrate this.


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