Christine Branch (l) measures the infrared spectrum of her unknown solute with the help of lab assistant Brittany Austin (r) in General Chemistry 110 lab.
Infrared spectroscopy (IR) is based on the interaction of the vibrational frequencies of individual (and groups of) bonds within a molecule with the infrared portion of the electromagnetic spectrum. The technique is most useful for discerning which functional groups are present in a molecule. Our instrument is a Fourier-Transform Thermo Electron IR 100, acquired in 2002 with funding from the National Science Foundation. It is equipped with an Attenuated Total Reflectance (ATR) device, so that spectra may be measured quickly from the pure sample, without making KBr pellets or Nujol mulls.