How to find the concentration of CO2 in 1M NAOH solution?

[Pollyannaism]

I done the absorption experiment i.e absorption of CO2 from air using 1M NaOH .Can anyone please tell how to analyse the Liquid sample after absorption.

I found the concentration of NaOH after and before the experiment,difference in Concentration gives the concentration of CO2.is it the reight approach.
Any suggestion is appreciated..

 

[Borek]

I found the concentration of NaOH after

How?

This is not a wrong approach, it is just a tricky problem. Compare Warder titration.

 

[Pollyannaism]

Thank you for replying..

I directly titrate the NaOH solution at inlet and also liquid solution from the column( outlet solution )against the HCl to find the concentration.My doubt is that when I tirate NaOH solution of the outlet ( contains Na2CO3 + unreacted NaOH) against HCl ,Na2cO3 reacts with Hcl to form NaOH again and CO2 will bubble out.So after doing the titration I am getting almost the same concentration(no significant difference)in both the solution.

 

[Borek]

Have you read the linked page? It is likely a matter of choosing correct indicator.