Effect of pH and temperature on reaction kinetics of CO2 and NaOH 1

[NeedAHoliday]

Dear All,

Could anyone either supply or direct me to a source of information for the reaction potential of CO2 with NaOH that encompasses the effect both pH temperature and pressure has on the kinetics of the reaction. I understand that at pH of 9.5-10 and up that the CO2 will have a high rate of reaction as opposed to pH of of 7-8 but I would like to quantify this.

Predominantly if there is a source out there showing reaction curves (with accompanying theory/discussion hopefully) vs T, P, pH, etc, this would be exactly what I am after.

Cheers,

 

[25362]

One probable good source: Principles of Modern Chemistry by Oxtoby-Nachtrieb (Chicago University), International Edition, Sounders Golden Sunburst Series, ISBN 0-03-047422-1, Library of Congress Catalog Card Number:90-053311, on the chapter of polyprotic acids. Good luck.

 

[m777182]

I assume that it is about gas liquid reaction.In such a case gas has to be absorbed first and then the reaction follows. In the following book
Danckwerts P. V.,Gas-Liquid Reactions,(1970),McGraw-Hill
you will find a good basis for understanding the dynamics of this type of reactions.
If you like calculations then find the book by J. Ricci, Hydrogen Ion concentration, and you will be able to produce exact curves relating reaction of NaOH with CO2 including the effect of T. But there is one thing that you should know: calculations hold for pure systems.
M777182

 

[PeterAB]

Temperature and pH have a precisely quantifiable effect on the partial pressure of CO2 above a caustic/sodium carbonate/sodium bicarbonate solution. The ratio of H2CO3, HCO3- and CO3= in solution are given by the pH and the carbonic acid first and second acid dissociation constants, themselves a function of temperature. Knowing the concentration of undissociated H2CO3 in solution allows you to calculate the partial pressure of CO2 over the solution via Henry's Law Constant, which is really a strong function of temperature rather than truly constant. The distance from equilibrium will be one factor affecting the reaction rate. Another factor is the gas-liquid interfacial area available. Perry (p. 18-44 in fifth ed.)also has a discussion on the kinetics of this reaction, quoting Sherwood and Pigford that "the controlling step is a slow pseudo-first order irreversible reaction between dissolved CO2 and OH-" and gives a relation for kga.