carboxylic acid/koh calculating titration curves

Mar 2019
the world

I am attempting to calculate various theoretical tittration curves for a strong base weak acid titration: similar to the one in this wiki:

I don't have any difficulty calculating the inital ph or the pH at/after the equivalence point. For the calculations of pH before the equivalence point, it seems the hasselbalch equation ( can be used. There is also the derived approximation in the wiki that can be used.

The hasselbalch equation just seems to be outputting the same curve, regardless of concentrations, which does not match with the rest of the calculations. The approximation in the wiki does not seem to output anything useful.

Here is a excel sheet with my current work. Ignore the graph as it does not transfer to google sheets correctly.

correct graph:

Any help would be appreciated.
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