characterization of a reaction

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characterization of a reaction

Postby madisondesilva1c » Fri Mar 01, 2019 3:14 pm

Given any example that is not intuitive or a reaction in everyday life such as a diamond going to graphite in a very slow manner, how is one to predict whether thermodynamics or kinetics is able to control that said reaction given the details of both?

Kevin ODonnell 2B
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Joined: Fri Sep 28, 2018 12:24 am

Re: characterization of a reaction

Postby Kevin ODonnell 2B » Fri Mar 01, 2019 8:08 pm

For thermodynamic favorability:
ΔG>0, the reaction is nonspontaneous in the forward direction, not thermodynamically favorable

ΔG<0, the reaction is spontaneous in the forward direction, thermodynamically favorable

However, a reaction can be thermodynamically favorable yet still wont proceed due to kinetics. I believe kinetics just depend on the energy of activation hump, and if it can't get over that hump then the reaction won't proceed. So a reaction can be thermodynamic and kinetically favorable or thermodynamic and kinetically unfavorable. So first we would look at the gibbs free energy to see if it is thermodynamically favorable, and then look at the energy of activation to see if it is kinetically favorable and will proceed.

Madeline Motamedi 4I
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Joined: Fri Sep 28, 2018 12:23 am

Re: characterization of a reaction

Postby Madeline Motamedi 4I » Sun Mar 03, 2019 7:08 pm

So I believe you can determine if a reaction is favorable thermodynamically and kinetically. I don't think we have learned it yet but I know there is a large activation energy barrier that prevents the change from diamond to graphite.

Anna O 2C
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Joined: Fri Sep 28, 2018 12:19 am

Re: characterization of a reaction

Postby Anna O 2C » Sun Mar 03, 2019 10:25 pm

Kinetics and thermodynamics can both have a say in whether a reaction will proceed. When ΔG<0, the reaction will occur spontaneously and will be thermodynamically favorable, but not always kinetically favorable as seen in the case of diamonds and graphite which would have to overcome kinetic barriers to proceed without extra energy being added.

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