37. Analytical techniques
Start with Concept to understand a topic, then use Question Bank to check what you know.
Your progress
Sign in to see your mastery and mistakes.
37.1 Thin-layer chromatography
37.1.1And understand the terms
• Describe and understand the terms: (a) stationary phase, e.g. aluminium oxide (on a solid support); (b) mobile phase; a polar or non-polar solvent; (c) Rf value; (d) solvent front and baseline
37.1.2Rf values
• Interpret Rf values
37.1.3Differences in Rf values
• Explain the differences in Rf values in terms of interaction with the stationary phase and of relative solubility in the mobile phase
37.2 Gas / liquid chromatography
37.2.1And understand the terms
• Describe and understand the terms: (a) stationary phase; a high boiling point non-polar liquid (on a solid support); (b) mobile phase; an unreactive gas; (c) retention time
37.2.2Gas / liquid chromatograms
• Interpret gas / liquid chromatograms in terms of the percentage composition of a mixture
37.2.3Retention times
• Explain retention times in terms of interaction with the stationary phase
37.3 Carbon-13 NMR spectroscopy
37.3.1Carbon-13 NMR interpretation
• Analyse and interpret a carbon-13 NMR spectrum of a simple molecule to deduce:: (a) the different environments of the carbon atoms present; (b) the possible structures for the molecule
37.3.2Carbon-13 NMR peak count
• Predict or explain the number of peaks in a carbon-13 NMR spectrum for a given molecule
37.4 Proton NMR spectroscopy
37.4.1Proton NMR interpretation
• Interpret proton NMR to deduce proton environments, relative proton numbers, n + 1 splitting (singlet to multiplet), and possible structures.
37.4.2The chemical shifts and splitting patterns
• Predict the chemical shifts and splitting patterns of the protons in a given molecule
37.4.3Of tetramethylsilane, TMS, as the standard
• Describe the use of tetramethylsilane, TMS, as the standard for chemical shift measurements
37.4.4Need for deuterated solvents, e.g. CDCl ₃,
• State the need for deuterated solvents, e.g. CDCl ₃, when obtaining a proton NMR spectrum
37.4.5O-H and N-H proton exchange with D2O
• Describe the identification of O–H and N–H protons by proton exchange using D₂O