Organic Chemistry Reaction Mechanisms

10 min read · Learn SN1, SN2, E1, and E2 with clarity.

Back to Blog Listing
Chemistry

Organic Chemistry Reaction Mechanisms

Mechanisms explain the steps behind reaction outcomes.

Mechanisms are the “how” behind reaction outcomes. In VCE Chemistry, you’ll be expected to match a given set of conditions (and substrate type) with the most likely mechanism and then describe the steps.

SN1 vs SN2

  • SN1: two-step pathway, often forms a carbocation intermediate.
  • SN2: one-step concerted process, typically involves backside attack.

E1 vs E2

  • E1: two-step elimination often via a carbocation.
  • E2: one-step elimination requiring an appropriate base and geometry.

How to Study Mechanisms

Instead of memorising in isolation, compare each pair (SN1/SN2, E1/E2). Build a table that lists rate, intermediate/transition state, typical substrate/base, and expected product outcomes.