Diamond/Graphite

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Leah Savage 2F
Posts: 74
Joined: Fri Sep 29, 2017 7:06 am

Diamond/Graphite

Postby Leah Savage 2F » Tue Mar 06, 2018 5:51 pm

What does it mean that diamond is kinetically stable with respect to graphite but thermodynamically unstable?

Ridhi Ravichandran 1E
Posts: 35
Joined: Sat Jul 22, 2017 3:01 am

Re: Diamond/Graphite

Postby Ridhi Ravichandran 1E » Tue Mar 06, 2018 5:59 pm

Because diamond is thermodynamically unstable with respect to graphite, this means that delta G is negative for this process and diamond will spontaneously turn into graphite. However, because this process is also kinetically stable, this means that the process will occur very slowly. The book is just pointing out that while conversion to graphite is favorable, it does not necessarily mean that the reaction will occur quickly. In fact, this reaction will occur very slowly.

Amanda Wu 2C
Posts: 31
Joined: Sat Jul 22, 2017 3:00 am

Re: Diamond/Graphite

Postby Amanda Wu 2C » Wed Mar 07, 2018 4:22 pm

Although diamond is thermodynamically unstable because delta G is negative (the reaction is spontaneous) and diamond has a higher energy than graphite, diamond is considered kinetically stable because the pathway in which diamond becomes graphite has a large activation energy barrier that prevents its ready conversion to graphite. Thus, under ambient conditions, diamond won't change to graphite even though graphite is thermodynamically more stable than diamond.

Clara Hu 1G
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Joined: Sat Jul 22, 2017 3:00 am
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Re: Diamond/Graphite

Postby Clara Hu 1G » Wed Mar 07, 2018 5:13 pm

According to thermodynamics, the reaction from diamond to graphite is spontaneous and favorable. However, because kinetics rather than thermodynamics is controlling this reaction, it occurs extremely slowly. So, diamond is kinetically stable, but thermodynamically unstable.

Pooja Nair 1C
Posts: 55
Joined: Thu Jul 13, 2017 3:00 am

Re: Diamond/Graphite

Postby Pooja Nair 1C » Fri Mar 16, 2018 1:58 am

Diamond is thermodynamically unstable because delta G for diamond to graphite is negative and therefore spontaneous, but the transition from diamond to graphite has a large activation energy barrier, so diamond is not likely to transition on its own to graphite and is therefore kinetically stable.


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