Assess students' ability to recall characteristic IR absorption frequency ranges (cm⁻¹) and concise diagnostic features for common functional groups: carbonyls (distinguish ketone, ester, amide, conjugation effects), alcohols, amines (primary/secondary N–H patterns), nitriles, aromatics, alkenes, and alkynes. Require each answer to give a typical range and 1–2 distinguishing notes (e.g., broad vs. sharp, number of N–H peaks, conjugation shifts, terminal ≡C–H).