• 072920 77839
  • info@smartachievers.in
Menu
Back
  • JEE ADVANCE
  • JEE MAIN
  • NEET
  • BITSAT
  • CBSE BOARD
  • UP BOARD
  • CUET
JEE ADVANCE
  • CLASS XI - XII
  • CRASH COURSE
CRASH COURSE
JEE MAIN
  • CLASS XI - XII
  • CRASH COURSE
CRASH COURSE
NEET
  • CLASS XI - XII
  • CRASH COURSE
BITSAT
  • CLASS XI - XII
CBSE BOARD
  • CLASS IX
  • CLASS X
  • CLASS XI
  • CLASS XII
  • CLASS VI
  • CLASS VII
  • CLASS VIII
UP BOARD
  • CLASS IX
  • CLASS X
  • CLASS XI
  • CLASS XII
CUET
  • CRASH COURSE
Courses


Solution


Q.

The correct statement regarding nucleophilic substitution reaction in a chiral alkyl halide is:                   [2024]
1 Racemisation occurs in SN1 reaction and inversion occurs in SN2 reaction.  
2 Racemisation occurs in SN1 reaction and retention occurs in SN2 reaction.  
3 Retention occurs in SN1 reaction and inversion occurs in SN2 reaction.  
4 Racemisation occurs in both SN1 and SN2 reactions.  

Ans.

(1)

In SN1 reaction, carbocation is formed as an intermediate. Carbocation is planar and nucleophile may attack from either side of the plane. This gives a pair of enantiomers as reaction products i.e. product is racemic mixture. Although amount of inversion product is more than that of retention product because nucleophile starts attacking from back side even before leaving group has completely left the carbon. So in SN1 there is partial racemization.

In SN2, there is 100% inversion because nucleophile attacks from the side opposite to leaving group.