fusso
International Hazard
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Why can't chemists make a consensus about water's pka???
Water is the commonest liquid on earth. So its properties should be well studied and confirmed. But not its pKa. H2O<=>OH- has only 1 pKa. But 2
approaches, 2 values. One is 14 and the other is 15.7. Why can't chemists make a consensus on either one???
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Fulmen
International Hazard
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https://chem.libretexts.org/Textbook_Maps/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Fundamentals/What_is_the_pKa_of_water%3F
We're not banging rocks together here. We know how to put a man back together.
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Heptylene
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Its not a matter of consensus, but rather a matter of defintions. Have a look at this paper (Open access!).
Btw just because there is a confusion for some people (including you and me apparently) doesn't mean there isn't a consensus or that its unclear for
everyone.
EDIT: typo
[Edited on 1-11-2018 by Heptylene]
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unionised
International Hazard
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It's like asking why water has two freezing points, 0C and 32F.
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AJKOER
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Okay perhaps it's time for a moment of honesty. In the current particular context there's reference to an article with the title “Confusing
Quantitative Descriptions of BrønstedLowryAcidBase Equilibria in Chemistry Textbooks – A Critical Review and Clarifications for Chemical
Educators”.
But, in my opinion, there is actually no real (like in reality) confusion, but a seemingly generated confusion due to the general and unfortunate
(with respect to accuracy or truth being a victim) aspects of the science of teaching to makes things simple as a teaching preference (even if
elimination of select minor components could imply misleading global properties of the whole). In the particular context at hand, the article cites
the failure to introduce fundamental theoretical backgrounds relating to the science of activity coefficients and thermodynamic standard states early
on. Without this, Pka calculation may apparently run a foul when actually trying to make things in the real world as is frequently the case with
organic chemist.
So, in my opinion, it is not so much an issue with physical science, as perhaps an issue with the art and science of teaching (pedagogy) relating to
real science.
[Edited on 19-11-2018 by AJKOER]
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