Question

Give the major product formed when phenol is heated with concentrated H2SO4 and SO3. (There is more than one correct answer, but draw just one.)

Answer 1

See image attached and explanation

Step-by-step explanation:

The reaction of phenol with SO3/H2SO4 is an electrophilic reaction. The electrophile attacks portions of high electron density in the substrate phenol.

The -OH group activates phenol towards electrophilic substitution at the ortho and para positions, hence the product(s) formed in this reaction(only one product is shown here as required by the question).

The sulphonation of phenol using concentrated sulfuric acid at lower temperature yields majorly the ortho product whereas at higher temperature the para product predominates.