Consider the following anions
When attached to SP³ – hybridized carbon, their leaving group ability in nucleophilic substitution reaction decreases in the order :

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

i > ii > iii > iv

i > ii > iv > iii

iv > i > ii > iii

iv > iii > iii > i

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Good leaving group is the conjugate base of strong acid.

When attached to sp3−hybridized carbon, their leaving group ability in nucleophilic substitution reactions decreases in the order I>II>IV>III

I is best leaving group due to electron withdrawing (−I) effect of trifluoromethyl group and delocalization of negative charge over 3O atoms.

III is worst leaving group because negative charge is delocalized over C atoms.

The stabilization effect of resonance for the anion in which negative charge is delocalized over O atoms is more pronounced over the delocalization in which the negative charge is delocalized over C atoms.

II is better leaving group than IV because in II, the extent of delocalisation of negative charge is much more than the extent of delocalization in IV.

Watch 3-min video & get full concept clarity