How do the energy diagrams of SN1 and SN2 compare?
2D interactive · turn it, step through it, tap the parts
An interactive diagram of SN1 and SN2 between the same reactants and products: SN2 crosses one transition state with no intermediate, while SN1 climbs its highest barrier as the leaving group departs, rests in the carbocation's valley and crosses a small second barrier; a substitution slider raises SN2's barrier and lowers SN1's.