The polarity of the carbon-halogen bond is responsible for the nucleophilic substitution reactions of alkyl halides which mostly occur by S_(N)1 and S_(N)2 mechanisms. The rates of S_(N)2 reactions among other things are governed by steric factors while than of S_(N)1 reactions are governed by the stability of intermediate carbocations. chirality has a profound role in undersetanding the mechanism of S_(N)1 and S_(N)2 reactions. whereas S_(N)2 reactions of chiral alkyl halides are accompanied by inversion of configuration, S_(N)1 reactions are characterised by racemisation. Q. An S_(N)2 reaction at an asymmetric carbon of a compound always gives

The polarity of the carbon-halogen bond is responsible for the nucleop

1.	The polarity of the carbon-halogen bond is responsible for the nucleophilic substitution reactions of alkyl halides which mostly occur by S_(N)1 and S_(N)2 mechanisms. The rates of S_(N)2 reactions among other things are governed by steric factors while than of S_(N)1 reactions are governed by the stability of intermediate carbocations. chirality has a profound role in undersetanding the mechanism of S_(N)1 and S_(N)2 reactions. whereas S_(N)2 reactions of chiral alkyl halides are accompanied by inversion of configuration, S_(N)1 reactions are characterised by racemisation. Q. An S_(N)2 reaction at an asymmetric carbon of a compound always gives
Answer» an enantiomer of the substrate a product with opposite OPTICAL rotation a mixture of diastereomers a single stereoisomer. Solution :In `S_(N)2` reactions, inversion of CONFIGURATION occurs. Since the reactant and the product are not enantiomers, THEREFORE, the sign of optical rotation may or may not change and hence a single stereosiomerr is obtained, i.e., OPTION (d) is correct.