Problem 23P
Phenolphthalein is an acid–base indicator that is colorless below \(p H 8\) and red above \(p H 8\) Explain briefly why the first structure is colorless and the second structure is colored.
Equation Transcription:
Text Transcription:
pH 8
pH 8
OH
OH
HO-
OH
Step-by-Step Solution:
Solution:
Here we have to explain why phenolphthalein of pH<8 is colorless and pH >8 is red.
Step 1
In the compound A, the central C-atom is sp3, hybridized and this carbon atom is attached to the lactone ring oxygen. Due to the lack of delocalization in the molecule , it is colour less in acidic medium.
Step 2 of 2
