pka as function of ionic strength

User 259f5a561c

06-07-2005 22:46:09

It seems that the pka plugin gives pka values for an ionic strength of .10M (from comparing values to a table). Is there any way to get the pka for a different ionic strength, namely 0M?

User 851ac690a0

08-07-2005 08:13:53

It is nice that you managed to find such a good relation between predicted pKa and ionic strength.

pKa plugin can only calculate practical pKa values. Avarage standard deviation of our pKa prediction is between 1.0 - 0.2 pKa unit (depends on the molecule).

Ionic strength is not included explicitly in our pKa calculation.

Training set of pKa plugin containes both thermodynamic (I=0) and practical (I>0) pKa values.

Approximate relation derived between thermodynamic and practical pKa by Perrin et .al.:

‘pKa prediction for organic acids and bases, Chapman and Hall Ltd. 1981’

I hope it is help for you.