Question

What is the purpose of adding phenolphthalein to your Erlenmeyer flask prior to starting a titration?

Answer 1

Answer:

a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.

Explanation:

Phenolphthalein is an organic substance with chemical formula $C_{20}H_{14}O_{4}$.

It is a substance commonly used in acid-base titrations to indicate the end point in the titration because phenolphthalein is colorless in acidic solutions but turns a purplish-pink color in basic solutions.

In this way it helps visually to notice when the final point of the titration has been reached.