I'm a little boggled by a strangle titration problem that seems to contradict what I know about titration. I hope someone can resolve this seemingly strange phenomenon.(adsbygoogle = window.adsbygoogle || []).push({});

Suppose you have 0.1M of 50mL HCl.

You begin to add 0.1M of NaOH titrant.

Assume that Na and Cl ions do not hydrolyze.

Find the pH of the final solution after

a) 49.9999 mL

b) 50.0001 mL

of NaOH have been added.

Please note that the volumes described above are exactly precise. All figures are significant.

This is not a textbook problem. I made up this problem and came up with an answer of pH = 7 for both cases! How is this possible? The only equivalence point should occur when the volumes of acid/base are exactly identical, i.e. 50mL of titrant is added. But according to my calculations, pH = 7 also when these volumes of titrant are added. I don't think it's due to calculation errors. I have checked multiple times, but could still be wrong. It just seems bizarre.

I'm willing to show my work, but first I request someone can do this and confirm. If you get a different answer, then please just say so and I'll recheck my work.

Thanks!

BiP

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# Titration Paradox!

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