Increasing order of electron withdrawing power of following functional groups is : a. -CN b. -COOH c. -NO2 d. -I
- c < b < d < a
- c < a < b < d
- d < b < a < c
- a < b < c < d
Answer
(3) d < b < a < c
Solution
As per NCERT, the electron-withdrawing (−I) power of groups decreases in the order:
-NO2 > -CN > -COOH > -F > -Cl > -Br > -I
(-NO2 carries a positive charge on N; in –CN and –COOH the carbon is bonded to highly electronegative N / O; iodine is the least electronegative halogen.)
∴ Increasing order: -I < -COOH < -CN < -NO2, i.e. d < b < a < c
Answer: (3)