CO2 won't be released automatically fro NAHCO3 or Na2CO3. What are the other experimental conditions.

Dear Jai

As you can see in the attached paper, it has been mentioned . The mixed 3 ml of NaHCO3 and Na2CO3 solution (3 M) in the ratio of 73/27 (v/v) released 40 ppm m-3 CO2 in to the atmosphere of a closed vessel (Solarova and Pospisilova, 1997). I want to know the time course release of CO2? when and how much it released? is it decreases with time?

Kind regards

Sasan

my dear, please  explain 

As jai ghosh said CO2 will not be released automatically when you mix above said solutions unless you acidfy the solutions. If you want to quantify CO2 you can use GC or you can use pass CO2 through the solution of Ca(OH)2 solution and you can measure precipitated CaCO3 or you can use dragger tube

My dear Sasan: the article you are referring to doesn't seem to explain every thing. As I said before CO2 won't be released automatically unless you acidify or heat it very rigorously.

Dear Jai

Thanks for the answer, there are few publications such as the following which described the same: We put the described solution in closed vessels for two weeks and see a plant responses to high CO2 levels. I have not more information but as described in the following papers and few more, 40 g m-3 CO2 would be released from the solution, I want to know that this concentration of CO2 happens continuously or it would be the final amount of CO2 that released from the solution

Joshi P, Joshi N, Purohit S. 2006. Stomatal characteristics during micropropagation of Wrightia tomentosa. Biologia Plantarum 50, 275-278.

 Solarova, J. and J. Pospisilova. 1997. Effect of carbon dioxide enrichment during in vitro cultivation and acclimation to ex vitro conditions. Biol. Plant. 39:23-30.

Have you analyzed the headspace above a blank?

Hi Myron

Its same as the nkrmal atmosphere (380 ppm)

I think what is happening is a complex set of equilibria.

A small amount of carbonic acid will be in equilibrium with the bicarbonate ion.  The carbonic acid is in equilibrium with dissolved CO2, which in turn is in equilibrium with the headspace.  If you start with no CO2 in headspace, then I would expect there will be some shift of equilibrium toward CO2(g).  As far as kinetics, my understanding is that the inter conversion between CO2 and carbonic acid is usually the rate determining step.  Incidentally, these calculations are central to ocean acidification so you might find some computational approaches in that literature.

Beautiful answer by Myron. He has used the fundamentals of chemical reaction kinetics and explained the phenomenon. However, Sasan does not see the same in his microcosms experiments. He says that there is no change in the plant growth. Now, he would find some CO2 in the head space and that could be due to respiration by the plants and it escapes from the stomatal openings. 

I second the answer of Jai Gosh, because NaHCO3 and NaCO3 both are bases with high pH therefore CO2 can not release from both directly.