# How do sn1 reactions differ from sn2 reactions?

Apr 10, 2018

Consider the following points of difference.

#### Explanation:

SN1 Reaction

• It is Substitution Nucleophilic Unimolecular reaction.
• Proceeds in two steps.
• First step is the slow one involving dissociation of the substrate to form carbocation intermediate. Second step is the fast one in which the carbocation combines with the attacking Nucleophile.
• More stable carbocation $\rightarrow$ faster is the reaction
• It is favored by polar solvents.
• Mostly given by tertiary alkyl halides.
• It occurs with Racemization.
• It follows ${1}^{s t}$ order kinetics.
• Rate=k[R-X]

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SN2 Reaction

• It is Substitution Nucleophilic Bimolecular reaction.
• Proceeds in a single step which is the rate determining step.
• It is favored by non polar solvents.
• Mostly given by primary alkyl halides.
• Nucleophilic addition takes place from the opposite side of the Leaving group.
• It occurs with 100% inversion of configuration.
• It follows ${2}^{n d}$ order kinetics.
• Rate=k[R-X][Nu]

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