Understanding SN1 Mechanism in Chemistry

If SN2 is a group attack, SN1 is a solo mission — and the first step is the molecule

straight-up leaving. SN1 stands for Substitution Nucleophilic Unimolecular, and the key word here is unimolecular.

That means the rate depends on only ONE thing: the substrate. Step one is the slow,

rate-determining step. The leaving group leaves first, forming a carbocation.

Because carbocations are unstable, SN1 only works when they’re stabilized. That’s why tertiary

carbons are best, secondary sometimes works, and primary basically never does.

Once the carbocation forms, anything nearby can attack — the nucleophile jumps

in after the hard part is over. Now here’s the super testable detail: Carbocations are