Q. The compound that is most difficult to protonate is :
A) $H-O-H$
B) $H_3C-O-H$
C) $H_3C-O-CH_3$
D) $Ph-O-H$
Explanation
[Solution] In phenol the oxygen lone pair is delocalised into the ring, so it is least available for protonation. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.