What PH range should indicators be?

[matth87]

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I thought you want an indicator to be around the 1/2 equivalence point for a titration. Is this correct? Meaning you would want a ph range close to the pka of what your titrating?

I just got a question wrong because it said the PH range should be near the equivalence point. Is the the EQ point or the 1/2EQ point?

 

[Seraph 84]

You want the indicator pKa to be +/- 1 of the equivalence point pH. If you chose you're indicator to be around the half-equivalence point, then it wouldn't work because you haven't finished titrating you're acid/base.

 

[wanderer]

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If you are given the color change range for the indicator you want the entire range to be within the rapid rise/drop portion of the titration curve. For a strong acid/base indicator choice is not that important because there is a very large drop/rise.