Question

What do you observe in the above titration setup when 15 mL of the $NaOH$ with an unknown molarity is poured into the flask and then 5 drops of phenolphthalein indicator is added?

• A. A pinkish color will appear throughout the solution.
• B. A blue color will appear throughout the solution.
• C. There will be a temporary pinkish color that will dissipate.
• D. There will be a temporary blue color that will dissipate.
• E. There will not be a color change.

Answer 1

Answer: (A)

A pinkish color will appear throughout the solution.

In the above titration setup when 15 mL of the $NaOH$ with an unknown molarity is poured into the flask and then 5 drops of phenolphthalein indicator are added, a pinkish color will appear throughout the solution as the pH changes to basic.
In basic solution, phenolphthalein indicator gives pink color.
In acidic solution, phenolphthalein indicator gives a colorless solution.