diamond

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bellaha4F
Posts: 104
Joined: Wed Sep 18, 2019 12:20 am

diamond

Postby bellaha4F » Fri Feb 28, 2020 1:35 pm

can someone explain how a diamond is kinetically stable and thermodynamically unstable with respect to graphite?

Samuel G Rivera - Discussion 4I
Posts: 61
Joined: Sat Aug 17, 2019 12:16 am
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Re: diamond

Postby Samuel G Rivera - Discussion 4I » Fri Feb 28, 2020 1:49 pm

Diamond is kinetically stable in relation with graphite because there is an activation barrier for it to become graphite and energy would need to be added. It is thermodynamically unstable in relation to graphite because it is at a higher energy level then graphite.

Sanjana Borle 2K
Posts: 111
Joined: Fri Aug 09, 2019 12:15 am

Re: diamond

Postby Sanjana Borle 2K » Fri Feb 28, 2020 2:40 pm

Diamond is thermodynamically unstable because the delta G to go from Diamond to graphite is negative, which means the reaction for that to happen is favorable. However, it is kinetically stable, at least at standard temperature and pressure, because the rate of the reaction would be so slow that essentially nothing happened.

Jared Khoo 1G
Posts: 107
Joined: Wed Sep 18, 2019 12:16 am

Re: diamond

Postby Jared Khoo 1G » Sat Feb 29, 2020 3:46 pm

A diamond is thermodynamically unstable as it has a negative delta G value indicating that the reaction from diamond to graphite is favorable. however, it is kinetically stable as the reaction barrier is very high, so the reaction takes place at a very slow rate.
A diamond is not forever.

Nicholas_Gladkov_2J
Posts: 125
Joined: Sat Aug 17, 2019 12:17 am

Re: diamond

Postby Nicholas_Gladkov_2J » Sat Feb 29, 2020 9:38 pm

bellaha4F wrote:can someone explain how a diamond is kinetically stable and thermodynamically unstable with respect to graphite?


Think about the the activation energy.
The process is favored (delta G is negative) for diamond to become graphite, but because of the large energy barrier (as it is kinetically trapped), it is kinetically stable with respect to graphite, but it is thermodynamically unstable.


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