Q. According to Gahn-Ingold-Prelog sequence rules, the correct order of priority for the given group is

A) $- COOH > - CH_{2}OH > - OH > - CHO$
B) $- COOH > - CHO > - CH_{2}OH > - OH$
C) $- OH > - CH_{2}OH > - CHO > - COOH$
D) $- OH > - COOH > - CHO > - CH_{2}OH$
Explanation

(d)
According to Cahn-Ingold-Prelog sequence rules, the priority of groups is decided by the atomic number of their atoms. When the atom (which is directly attached to the asymmetric carbon atom) of a group has higher atomic number, then the group gets higher priority. Groups which atoms of comparable atomic number having double or triple bond, have high priority than those have single bond.
Hence, the order of priority of group is
$- OH > - COOH > - CHO > - CH_{2}OH$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.