Question

When phenolphthalein is added to $NaOH$ solution, the colour changes to:

• A. pink
• B. red
• C. green
• D. black

Answer 1

The correct option is A pink

In alkaline solution, phenolphthalein gives pink color as it works as an indicator which shows its endpoint when it reacts with hydroxide ions of the base. It is a commonly used indicator in acid-base titrations. In acidic solution when acid is added, phenolphthalein gives a colorless solution.

Option A is correct.