[Neverquit]

Hi,

it seems  pretty clear that solubility of CO2(g) in water is 1.45 g/L at 25 °C, 100 kPa.

So that would be 1.45g/44.01M =0.0329 mol L^-1.

If I want to find the maximum moles of CO2 I can get it the 1L of water at 25 degrees (keeping the temparature constant)  what would be the pressure? Is there a formula?

Thanks,
Neverquit

[AWK]

http://www.elmhurst.edu/~chm/vchembook/174temppres.html

[Neverquit]

Hi,

is it correct to use Henry's law to find the maximum moles of CO2 that will disslove in 1L of H2O at 25 degreesC?

K=p/x
 
c=moles
p=100
k=29.41 L.atm/mol

then
x=p/K

=100/29.41

=3.4002mols

Would this be correct?

Thanks,
Neverquit

[DevaDevil]

okay, back to your initial question.

If you increase the pressure, then yes, you will dissolve more CO₂.
What is the maximum pressure you can bring the water at before it turns solid at 25^oC? (find a phase diagram)

then yes, you can use Henry's law; just make sure to have the units right!

100 kPa is not the same as 100 atm!!

[rabolisk]

You cannot use Henry's Law because Henry's Law is a limiting law that only applies in dilute solutions. In theory, at sufficiently high pressure, you can dissolve so much CO₂ that it becomes the solvent and water is the solute. You can pressurize the solution until it solidifies. There really is no such thing as "maximum" solubility at a given temperature, only a solubility at a given temperature and pressure.

[Neverquit]

Hi

this is what I have worked out so far:

Henry's formula:
K=p/x
 
x=moles
p=0.0060373 atm (The triple point of water)
k=29.41 L.atm/mol

then
x=p/K
=0.0060373/29.41
=2.0528x10^-4moles

Is this the maximum moles of CO2 that would dissolve in 1L of H20 in at 25degC?

Regards,
Neverquit

[DevaDevil]

triple point is not the maximum pressure at which water is still liquid, it is merely the point at which pressure and temperature the water has liquid, solid and gas phase in equilibrium with each other.

And rabolisk is right about the inability of Henry's law at concentrated solutions, and especially carbon dioxide cannot be used in henry's law as it reacts with water to for carbonate (equilibrium)

[Neverquit]

okay thanks.

So in that case the one would assume STP(ie 25degreesC) and solubility of CO2 in H2O as 1.45g/l or 1.45g/44.01M=0.0329Mol L^-1.

Regards,
NQ