How do i find the Pka from 4 points taken from a titration curve?

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How do i find the Pka from 4 points taken from a titration curve?

I did a titration using NaOH soln and an unknown and graphed it. Now I have to calculate the Pka from 4 points taken from the relatively flat portion of the titration curve. Something tells me to use the Henderson-Hasselbach eq but i dont know how for this titration. help please!

2007-04-19 16:25:24 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry

2 answers

The pKa of the unknown acid is the value of the pH at the titre equal to half of the volume needed to reach the equivalence point.

The use of H-H equation is correct. At the half way point, the salt content is equal to the acid content and the log factor goes to zero, leaving pH =pKa.

2007-04-19 23:38:39 · answer #1 · answered by Anonymous · 0⤊ 0⤋

Take the points and compute their slopes.

2007-04-20 01:47:38 · answer #2 · answered by ag_iitkgp 7 · 0⤊ 0⤋