Re: Continuations

On Thu, 18 Jul 2024 18:48:45 -0000 (UTC)
Thomas Koenig <tkoenig@netcologne.de> wrote:

Michael S <already5chosen@yahoo.com> schrieb:

On Thu, 18 Jul 2024 17:06:52 -0000 (UTC)
Thomas Koenig <tkoenig@netcologne.de> wrote: 

It does work far away from the equilibrium (which is the point). 

>
But how far?
Does it work for EA/RT outside of, say [-10:+12] ? 

 
Ea is almost always positive; if if was negative, it would mean that
a reaction is is slowed down by increasing temperature (and by this
don't mean the reverse reaction).

In the branch of physical chemistry that I was taught before switching
to completely different profession, that's not that rare.
For example, when temperature grows from 1500 degrees toward 1550
the transfer of phosphorus from molten steel to slag decelerates
greatly.

If you see that in data, that
means that the Arrhenius model is not applicable because there is
in fact no activation energy to overcome, that something strange
happens in thermodynamics (say, you get solid precipitation of
one component at a certain temperature) or that some there are
some intermediate steps which are not described in the model.
 
And to make sense, -Ea/(RT) is always less then zero.  Reasonable
example: Ea = 30 kJ/mol, R=8.314, T=600 K gives you -6.01 as the
argument of the exponent, so the term is then ~ 0.002444 .

So, something like [-10:0] ?