Dear Yurii V Geletii,

The methods are beautiful that used in the measurement of the dissocation/formation rate of water.

The kinetics of proton transfer reaction is super fast, it can be measured with relaxation methods ("temperature or field-jump" methods and from the line-broadening of Raman or ESR/NMR signal).

The neutralization reaction was first examined by Eigen (ref. below, 1955), They used a so called "field-jump" method. In the field-jump method the dissociation constant of the electrolyte can be increased with external electric field.

Ert and Gerischer (ref. below) also studied the dissociation rate of H2O and D2O, they used temperature -jump method.

I read an excellent book about this topic:

Hans Strehlow: Rapid Reactions in Solution, VCH, 1992

All the references below are reviewed in this book.

Ref. in german languauge:

M. Eigen, L. De Maeyer, Z. Elektrochem, 1955, 59, 986

G. Ertl, H. Gericher, Z. Elektrochem, 1961, 65, 629

G. Ertl, H. Gericher, Z. Elektrochem, 1962, 66, 560

M. Eigen, G Ilgenfritz, W. Kruse, Chemische Berichte, 1965, 98,1623

Ref. in english:

M. M. Kreevoy, C. A. Mead, J. Am. Chem. Soc. 1962, 84, 4596

M. M. Kreevoy, C. A. Mead, Disc. Faraday Soc. 1965, 39, 166

A. K. Covington, J. G. Freeman, T. H. Lilley, J. Phys. Chem. 1970, 74, 3773

D. E. Irish, O. Puzic, J. Solution Chem. 1981, 10, 377

H. Strehlow, I. Wagner, P. Hildebrandt, Ber. Bunsenges, 1983, 87, 516

B. Cohen, S. Weiss, J. Phys. Chem. 1983, 87, 3606

B. Cohen, S. Weiss, J. Phys. Chem. 1984, 88, 3159

H. Strehlow, Ber. Bunsenges, 1989, 93, 617

H. Strehlow, P. Hildebrandt, Ber. Bunsenges, 1990, 94, 173

Dear Yurii V Geletii,

The methods are beautiful that used in the measurement of the dissocation/formation rate of water.

The kinetics of proton transfer reaction is super fast, it can be measured with relaxation methods ("temperature or field-jump" methods and from the line-broadening of Raman or ESR/NMR signal).

The neutralization reaction was first examined by Eigen (ref. below, 1955), They used a so called "field-jump" method. In the field-jump method the dissociation constant of the electrolyte can be increased with external electric field.

Ert and Gerischer (ref. below) also studied the dissociation rate of H2O and D2O, they used temperature -jump method.

I read an excellent book about this topic:

Hans Strehlow: Rapid Reactions in Solution, VCH, 1992

All the references below are reviewed in this book.

Ref. in german languauge:

M. Eigen, L. De Maeyer, Z. Elektrochem, 1955, 59, 986

G. Ertl, H. Gericher, Z. Elektrochem, 1961, 65, 629

G. Ertl, H. Gericher, Z. Elektrochem, 1962, 66, 560

M. Eigen, G Ilgenfritz, W. Kruse, Chemische Berichte, 1965, 98,1623

Ref. in english:

M. M. Kreevoy, C. A. Mead, J. Am. Chem. Soc. 1962, 84, 4596

M. M. Kreevoy, C. A. Mead, Disc. Faraday Soc. 1965, 39, 166

A. K. Covington, J. G. Freeman, T. H. Lilley, J. Phys. Chem. 1970, 74, 3773

D. E. Irish, O. Puzic, J. Solution Chem. 1981, 10, 377

H. Strehlow, I. Wagner, P. Hildebrandt, Ber. Bunsenges, 1983, 87, 516

B. Cohen, S. Weiss, J. Phys. Chem. 1983, 87, 3606

B. Cohen, S. Weiss, J. Phys. Chem. 1984, 88, 3159

H. Strehlow, Ber. Bunsenges, 1989, 93, 617

H. Strehlow, P. Hildebrandt, Ber. Bunsenges, 1990, 94, 173

Dear Yurii V Geletii,

"if you build a kinetic model of some process involving acid base equilibria, you have to assign formal reaction rate constants for this equilibrium."

Why do you need to use formal rate constant in your model...if the neutralization reaction has an exact rate constant?

Thanks, Peter,

I know the basics of experimental studies of ultrafast reaction ("unmeasurable" as called by Eigen). Thanks for references. I read some of them and many others. So far I don't have a clear answer on "the neutralization reaction has an exact rate constant." I intentionally did not express my own opinion on values  reported in the literature.  Therefore, I asked the expert's opinion. I used the term "formal" reaction rate constants because the neutralization reaction can be written in different way, such as water autoionization: 2 H2O = H3O+ + HO-. What is for your opinion the most reliable values of the rate constants of the equilibrium H+ + HO- = H2O?

Thanks again for references. 

Dear Yurii V Geletii,

I see the problem... 2H2O = H3O+ + HO-

The reactions of dimers/oligomers can not be isolated in this measurements.

I read some of this paper a long time ago. I guess the exact rate coefficient of the individual H2O H+ + OH- reaction could be obtained from gas kinetic measurements (at low pressure). But you and other need the rate coefficient in solution, where is impossible to distinguish the reaction of the monomer (H2O H+ + OH- ). I guess the tunneling effect is very important in this reactions, so the molecular dynamic (classical) simulations would be inappropriate for the problem due to their classical nature.

It is derived from pH and pKa.

Dear Jerry, pH and pK are the thermodynamic parameters. I'm asking about the rate constants (kinetic parameters).

Dear Yurii V Geletii

I came here from this topic: https://www.researchgate.net/post/how_can_we_involve_acidic_equilibrium_reactions_with_their_PKa_values_in_our_reaction_kinetics2

I googled value k=1.4e11 L/mol/sec for H+ + OH- = H2O (in "Fundamentals of Chemistry. Online tutorial.", see http://www.hemi.nsu.ru/ucheb214.htm , in Russian).

Some time ago I was seen the value 1.3e11, but sorry, I did not saved proper Reference.

And googled one more reference:

https://kinetics.nist.gov/kinetics/ReactionSearch?r0=1310732&r1=7647010&r2=0&r3=0&r4=0&p0=7647145&p1=7732185&p2=0&p3=0&p4=0&expandResults=true&

Value of k is equal to 2.8e-10 cm3/molecule/sec or ~1.7e11 L/mol/sec.

Here data presented from "Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling. Evaluation Number 12", see https://jpldataeval.jpl.nasa.gov/pdf/Atmos97_Anotated.pdf , page 39.

Dear Andriy Kytsya ,

the first reference is the textbook for high school students. The second one is for a gas phase.