Spectroscopy guides
Three step-by-step guides to the spectra you meet in organic chemistry. Each one has annotated spectra redrawn from reference data, worked examples and a practice quiz.
Quick answer: Use MS for the molecular formula, IR for functional groups, and NMR for the carbon–hydrogen framework. Combine all three to solve a structure.
On this page
Guides
Solve a structure: the workflow
- MS: find M⁺ and the molecular formula (formula finder).
- Calculate the degree of unsaturation.
- IR: identify functional groups (IR chart).
- ¹³C and ¹H NMR: count environments, read shifts, integrals and splitting; check with structure to NMR.
Practice quiz
Tap an answer to check it.
1. Which technique gives the molecular mass?
The molecular ion in a mass spectrum gives the molecular mass.
Frequently asked questions
Which spectroscopy should I learn first?
Start with IR (functional groups), then mass spectrometry (molecular formula), then NMR, which gives the most structural detail.
References and data sources
- Pavia, Lampman, Kriz & Vyvyan, Introduction to Spectroscopy, 5th ed.
- Silverstein, Webster & Kiemle, Spectrometric Identification of Organic Compounds, 8th ed.
Spectra on this page are redrawn schematically from the reference data above (peak positions and approximate relative intensities) for teaching; check the original database entry before citing exact intensities.