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Topic: kinetically inhibited reaction  (Read 9874 times)

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Offline aeacfm

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kinetically inhibited reaction
« on: October 09, 2010, 10:09:45 AM »
what is meant by kinetically inhibited reaction?

Offline DevaDevil

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Re: kinetically inhibited reaction
« Reply #1 on: October 11, 2010, 06:15:50 AM »
that is it not diffusion limited;

in other words, that there are plenty of reactants present and the reaction is just slower than the diffusion of reactants to the reaction site.

Offline aeacfm

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Re: kinetically inhibited reaction
« Reply #2 on: October 11, 2010, 07:14:58 AM »
that is it not diffusion limited;

in other words, that there are plenty of reactants present and the reaction is just slower than the diffusion of reactants to the reaction site.

suppose in electrolysis ... i think they are diffusion is better so what make electrode reaction kinetically inhibited .

Offline DevaDevil

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Re: kinetically inhibited reaction
« Reply #3 on: October 11, 2010, 10:20:49 AM »
reaction kinetcs is in essence how fast a reaction can go.

what therefore kinetically inhibited means is that the intrinsic reaction rate is very slow, so that all other processes that can influence the reaction rate (mass transfer for example) are fast enough to not negatively impact the reaction rate.

as for what it can cause a reaction to be kinetically limited... low temperature, low pressure etc., or just simply that the reactants themselves do not want to react with one another.


In water electrolysis water (the reactant) is SO abundant, that mass transport limitations are negligible and thus the reaction (if it goes) is controlled purely by kinetics.

Offline aeacfm

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Re: kinetically inhibited reaction
« Reply #4 on: October 21, 2010, 04:03:56 PM »

In water electrolysis water (the reactant) is SO abundant, that mass transport limitations are negligible and thus the reaction (if it goes) is controlled purely by kinetics.


sorry but i cant understand what do you mean by this satatement

Offline DevaDevil

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Re: kinetically inhibited reaction
« Reply #5 on: October 22, 2010, 05:52:50 AM »
what I mean is that there is so much water (which is the main reactant in electrolysis; water --> hydrogen + oxygen), that mass flow limitation is minimal.
This means that the reaction rate is determined by the reaction kinetics, rather than how fast the reactant can reach the reaction site. In other words, the reaction is kinetically inhibited (limited).

Offline aeacfm

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Re: kinetically inhibited reaction
« Reply #6 on: October 26, 2010, 07:08:38 AM »
aha ,
ok Dr  so this give us why some concentrated solutions electrolysed more than the dilutes one .

 so can in increase  the mass transfere to electrode in case of diluted solution ?may be agitation or some thing else

Offline DevaDevil

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Re: kinetically inhibited reaction
« Reply #7 on: October 26, 2010, 12:21:55 PM »
if mass transfer is limiting in your reaction, you can force convection to the reaction site (electrode) by stirring, or rotating the electrode if it is a disc-shape.

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