Question

Phenol Is Heated With Phthalic Anhydride In Presence Of Conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$. The Product Gives Pink Colour With Alkali. The Product Is:

Answer 1

Reaction of Phenol with Phthalic anhydride:

• When Phenol is treated with Phthalic anhydride, it will lead to the formation of Phenolphthalein.
• Phenolphthalein when in an acidic medium remains colourless, but in a basic medium, its colour changes to pink.
• It is used as indicator for the test of acidic and basic medium.

So, The product is Phenolphthalein.