Q.
Give the order of ease of the esterification of the following acids
A) $I > II > III > IV$
B) $IV > III > II > I$
C) $II > I > IV > III$
D) $I > II > III > IV$
Explanation
(a)
$As - CH_{3}$ group has a strong $+ I$ effect and $–OCH_{3}$ group has a weak $–I$ but strong $+ R$ effect, hence they increase the electron density on oxygen atom and $O - H$ bond becomes stronger. On the other hand, $- NO_{2}$ group has a strong $–I$ and $–R$ effect. It withdraws electrons from benzene ring as well as oxygen atom of $–OH$ group and proton is easily removed. Order of esterification is $I > II > III > IV$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.