Lesson Plan

• Describe characteristic chemical tests for common organic functional groups.
• Interpret IR, ¹H NMR and UV‑Vis spectra to identify functional groups.
• Apply an integrated workflow to determine the structure of an unknown organic compound.
• Compare the advantages and limitations of classical tests versus spectroscopic techniques.

• Projector and screen for slides.
• Sample set of organic compounds (alcohol, phenol, aldehyde, ketone, acid, amine, ester).
• Reagents for classical tests (HCl/ZnCl₂, FeCl₃, Tollens’ reagent, NaHCO₃, H₂SO₄, I₂/NaOH).
• IR spectrometer (or pre‑recorded spectra) and speaker.
• ¹H NMR spectra handouts or spectrometer access.
• UV‑Vis spectrometer (or printed spectra).
• Worksheets for data analysis and structure proposal.

Begin with a quick demonstration of a colour change in the Lucas test to spark curiosity about how functional groups can be “seen”. Review students’ prior experience with simple qualitative tests and basic IR peaks. State that today they will learn to combine these tests with modern spectroscopy to reliably identify unknown compounds.

1. Do‑now (5 '): Students write down any functional‑group tests they recall and predict the observable result.
2. Mini‑lecture (10 '): Overview of classical tests and key spectroscopic signatures (IR, ¹H NMR, UV‑Vis).
3. Hands‑on stations (20 '): Small groups rotate through stations performing Lucas, Ferric‑chloride, Tollens’, and NaHCO₃ tests on provided samples; record observations.
4. Spectra analysis (15 '): Using projected IR and NMR spectra, students match peaks to functional groups and fill a worksheet.
5. Integrated workflow activity (10 '): In pairs, students follow the 6‑step decision‑making flowchart to propose a structure for an unknown sample.
6. Check for understanding (5 '): Quick “exit ticket” – one sentence summarising when you would choose a spectroscopic method over a classical test.

Recap the complementary role of chemical tests and spectroscopy in functional‑group identification. Collect exit tickets and discuss a few responses to reinforce the success criteria. Assign homework: analyse a provided set of IR and ¹H NMR spectra to identify the functional groups and suggest a plausible structure.