Question

For a rxn involving a strong base and a weak acid, which of the following indicators would be best to indicate the endpoint fo the titration? (Circle the correct answer)

-Pnenolphtalein (pKa=9.7)
-Bromothymol blue (pKa= 7.1)
-Bromocresol green (pKa= 4.7)
-Methyl yellow (pKa= 3.3)"

Answer 1

The best indicator for a titration involving a strong base and a weak acid is phenolphthalein with a pKa of 9.7.

Step-by-step explanation:

For a reaction involving a strong base and a weak acid, the best indicator to indicate the endpoint of the titration would be phenolphthalein with a pKa of 9.7. Phenolphthalein has a pKa value greater than 7.0, which is the pH at the equivalence point of a weak acid titration. It exhibits a sharp color change around this pH value, making it an effective indicator for this type of titration.