Summary Analytical Techniques: IR, Mass Spectrometry, NMR & Chromatography – A-Level/IB Chemistry Notes

This document provides comprehensive A-Level/IB Chemistry notes on analytical techniques, including spectroscopy and chromatography, essential for identifying and characterizing organic compounds. Key Topics Covered: Infrared (IR) Spectroscopy: Identifies functional groups by measuring absorption of IR radiation at characteristic frequencies. Mass Spectrometry: Molecular fragmentation patterns (e.g., M⁺ peak, base peak) to determine molecular mass and structure. Example: Ethanol fragments into CH₃⁺ (m/z=15), CH₃CH₂⁺ (m/z=29), and CH₃CH₂OH⁺ (m/z=46). Chromatography: Thin-Layer Chromatography (TLC): Calculates Rf values to identify components. Gas Chromatography (GC): Separates volatile compounds by retention time; peak area indicates concentration. Nuclear Magnetic Resonance (NMR) Spectroscopy: ¹H NMR: Chemical shifts, integration (H count), and spin-spin splitting (n+1 rule). ¹³C NMR: Identifies unique carbon environments. Reference Compounds: TMS (tetramethylsilane) and CDCl₃ (deuterated solvent). Why This Document is Useful: Exam-Focused – Covers practical techniques and data interpretation for exams. Clear Diagrams & Examples – Illustrates fragmentation (mass spec) and NMR splitting patterns. Lab Techniques – Explains Rf values, retention times, and solvent use (D₂O for proton exchange). Structured & Concise – Ideal for quick revision before tests. Perfect for students analyzing organic compounds or teachers preparing lessons on analytical chemistry!