An infrared spectrum measures the vibrational frequencies of a molecule. Each "functional group" within the molecule (such as an alcohol group or a carbonyl group) absorb light at a particular frequency. Thus, this experiment tells you what functional groups exist within your molecule--a large step toward determining its structure.
Perkin Elmer Spectrum RX-1 FTIR Spectrometer with ATR accessory
Perkin Elmer 1600 Series FTIR Spectrometer
Page last modified May 11, 2011