What characteristic of a strong acid-strong base titration curve allows for the use of multiple acid-base indicators to determine the equivalence point?

The steep slope of the titration curve around the equivalence point allows multiple indicators to be used.

For the titration of a weak base with a strong acid, why is the pH at the equivalence point less than 7?

At the equivalence point, the weak base has been converted to its conjugate acid, which is acidic and lowers the pH.

Grade 11th Grade · Science · 30 min

I can interpret a titration curve to determine the equivalence point for strong acids and strong bases.

Khan Academy Organic Chemistry · 7:10

Titration curves and acid-base indicators | Chemistry | Khan Academy

3 key concepts

1
An indicator changes color in a specific pH range, and methyl red is an indicator that goes from red to yellow over a pH range of about 4.4 to 6.2.
2
For the titration of a weak acid with a strong base, the pH is greater than 7 at the equivalence point, so phenolphthalein would work well as an indicator because it changes in a range of 8 to 10.
3
When titrating a weak base with a strong acid, the pH at the equivalence point is less than 7, so methyl red would be a good indicator to use.

3 questions · Multiple choice & Short answer

Quick comprehension check

“According to the video, what is the pH at the equivalence point when titrating a strong acid with a strong base?”

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