On adding phenolphthalein indicator to a colourless solution, no change is observed. What is the nature of this solution? Explanation: Color of phenolphthalein indicator will not change with acidic or neutral solution.

When phenolphthalein indicator is added to a colorless?

Phenolphthalein is naturally colorless but turns pink in alkaline solutions. The compound remains colorless throughout the range of acidic pH levels but begins to turn pink at a pH level of 8.2 and continues to a bright magenta at pH 10 and above.

Which phenolphthalein indicator is added to a colorless solution?

Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. Phenolphthalein changes colour sharply at about pH 8. For most purposes, this means that it is pink in alkaline solutions and colourless in acidic solutions.