Assess students' ability to identify and predict whether a reaction follows SN1, SN2, E1, or E2 pathways based on substrate structure, nucleophile/base strength, solvent and temperature, and leaving-group ability; require mechanistic justification (including rate law, intermediates, stereochemical and regiochemical outcomes), recognition of carbocation formation and rearrangements, and interpretation of experimental evidence such as kinetics and stereochemical probes.