pH at equivalence point and concentrations

[m25]

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How do pH at equivalence point change with the initial concentration of analyte and titrant?

For example, if we had 1M of weak acid titrated by 1M of NaOH versus 2M of weak acid titrated by 1M, I know that the volume of NaOH required will be twice as much at equivalence point, but how do pH at equivalence point change and why? And what happens if I have 1M of weak acid titrated by 2M of NaOH, and 2M of weak acid titrated by 2M of NaOH??

 

[DrDreams]

The molar equivalents will always be the same. If you are titrating a weak acid with a strong base, at equivalence the pH will always be greater 7 because the base is a strong base, and basically a little overshoot occurs. If you have an even more concentrated base with 1M weak acid, the molar equivalents will be the same, hence half the volume, but the pH at equivalence will still be basic.

Remember equivalence is when [H+]=[OH-] but when you go beyond this point, more acid that had reached its equivalent is being turned into its conjugate base as well.

It is the same case for all the cases.