I´m carrying out the Boehm titration to determine the amount of the acidic functional groups present on the surface of activated carbon. For this, I am doing is the following: I placed 0.02 gr of carbon in 20 ml of 0.01M solution (NaOH or NaHCO3) and 10 ml for the Na2CO3 solution. For each case three replicas were prepared. This samples were kept under stirring for 24 h at 100 rpm and 30°C. After this time, the carbon was separated from the solution by decantation. Then, 10 mL of that solution were taken, and the titration carried out adding a 0.01 M HCl solution until obtaining a pH of 7. The volume used of titrator solution was considered to calculate the quantity of functional groups. But I have had difficulties with these experiments because when I make the calculations of the carboxylic and lactonic groups I get a negative result. I don't know what is my mistake, that's why I'm writing to you. Could you please guide me. Thank you for your attention and collaboration.
Dear Aniyohana Valencia, these RG links deals with the question. My Regards
https://www.researchgate.net/post/Does_anyone_know_how_to_do_titration_Boehm_titration_to_determine_the_quantity_of_functional_groups_on_carbon_surface/amp
https://www.researchgate.net/post/What_are_the_calculations_involved_in_Boehm_Titration/amp
Hi;
Here is an interesting article: Surface acidity of carbons characterized by their continuous pK distribution and Boehm titration.
My regards
Hi there,
When you do the titration with HCl, please don't forget to account for the end point of each chemical with HCl. For example, HCl + NaOH is fine, because they are strong acid and base, the end point can be indicated by phenolphthalein. Now for the next case, Na2CO3 and NaHCO3 + HCl is not the titration between strong acid and base, you have to use the right indicator and simultaneously use pH Meter to check the end point at the same time. I have found this problem before when I was doing this titration. I hope this can help you.
Regards
You need to take care of influence of CO2 in air during Sample preparation, sample treatment (stirring time) & titration. Please refer the article https://www.mdpi.com/2311-5629/4/2/21/htm
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