In IR spectroscopy a beam of IR radiation is passed through a sample of a chemical.
The IR radiation is absorbed by the covalent bonds in the molecules, increasing their vibrational energy.
Bonds between different atoms absorb different frequencies of IR radiation.
Bonds in different places in a molecule absorb different frequencies too - so the O-H group in an alcohol and the O-H group in a carboxylic acid absorb different frequencies.
Wavenumber is the measure used for the frequency (it's just 1/wavelength).
An IR spectrometer produces a graph that shows you what frequencies of radiation the molecules are absorbing. So you can use it to identify the functional groups in a molecule.
The peaks show you where radiation is being absorbed - the 'peaks' on IR spectra are upside-down.
Comments
No comments have yet been made