The main difference between SN1 and E2 reactions is the mechanism by which they occur. SN1 reactions involve a two-step process where the leaving group leaves first, forming a carbocation intermediate, before the nucleophile attacks. E2 reactions, on the other hand, occur in a single step where the nucleophile simultaneously attacks the electrophilic carbon and the leaving group leaves.
The main factors that determine whether an SN1 or E2 reaction will occur are the substrate and the nucleophile/base. SN1 reactions prefer tertiary or secondary substrates and weak nucleophiles, while E2 reactions prefer primary or secondary substrates and strong bases.
In SN1 reactions, the rate-determining step is the formation of the carbocation intermediate, while in E2 reactions, the rate-determining step is the simultaneous attack of the nucleophile and departure of the leaving group.
Yes, both SN1 and E2 reactions can occur simultaneously, especially when the substrate is a tertiary or secondary halide and the nucleophile/base is a moderately strong one.
To predict the product of an SN1 or E2 reaction, it is important to consider the substrate, the nucleophile/base, and the reaction conditions. In some cases, both SN1 and E2 products may be formed, so it is important to determine which reaction is favored under the given conditions.