Calculate CO2 Dissolved in 5M KOH Solution | Pressure & Temp

[nst.john]

Can someone tell me how much CO2 I could dissolve in a 5M aqueous solution of potassium hydroxide and how to calculate this? This would be done at high pressure and low temperature, and if you can tell me what temperature and pressure would be optimal and why, or how to figure that out.

Thank you!

 

[Borek]

I would start treating it as a simple stoichiometry problem.

 

[nst.john]

Should I take into account Ka values and all that?

 

[nst.john]

By the way this is not a homework problem it is for a project I'm sorry I didn't specify

 

[Borek]

It is homework like, so it belongs in homework.

System is definitely capable of absorbing enough CO₂ to turn all KOH into potassium carbonate, and then some to turn potassium carbonate into hydrogen carbonate. For the latter step yes, you should take into account Ka2 and Henry's law.

But a lot depends on the system, whether it is allowed to get to equilibrium, plus you would need to take into account activity changes in the solution with ionic strength of over 7. The latter alone is enough to make any exact calculations difficult if not impossible.

 

[nst.john]

Sounds good thanks a lot.