SME
Analytical Chemistry · Problem type
Choosing an indicator
Use this for “Which indicator suits the titration of propanoic acid with NaOH, whose equivalence point is at pH 8.8?”
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Which indicator changes color across the pH at the equivalence point?
Tap a card, then tap its group.
Pick the indicator whose color change brackets the equivalence-point pH.
Assumptions
•
An indicator changes color over about two pH units, the range shown with its name.
•
Near the equivalence point the pH jumps steeply, so an indicator changing inside that jump marks it.
•
Each card gives the pH at the equivalence point: a weak acid’s base makes it above 7, a weak base’s acid below 7.
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