CO2 solubility in water as a function of pressure

[mariaxenia]

Hello All,

 

I have been puzzled recently with a question. I am interested in the solubility of CO2 in water as a function of pressure of the CO2.

 

Consider the following:

Microbes in a water-based solution produce CO2 at some unknown rate. This microbe/water solution is put into a container with little head space. The microbes produce CO2, the CO2 is dissolved in the water. As the microbes continue to produce CO2 the pressure of the gas in the container continues to increase, as well as the solubility.

 

The container is opened, the CO2 in the head space escapes, along with some CO2 dissolved in the solution. If we knew the final pressure before opening, what would the solubility of CO2 in the solution be?

 

Let's assume the initial air in the head space is negligible. Does anyone know of an equation that describes this system?

 

I have considered Henry's Law. My understanding is Henry's Law is used when dealing with partial pressures and more than one gas in a system, and it would not be applicable to this system. Could it still apply to this system?

 

Any advice would help. Thanks.

[Tartaglia]

Henry's law should still apply as you are still dealing with the eqm of CO2(g)/CO2(aq) and there is more than one gas anyway as water vapour is present

 

Some considerations - the behaviour of CO2 is not going to be ideal and in water it will react with water to form traces of carbonic acid in an eqm reaction and that will equilibrate giving H+ HCO3-

[timma]

Note:

 

Carbonic Acid, When heated, Becomes CO2, so if a yeild of CO2 is what you are looking for...

 

I shouldn't have to finish