Which of the following best describes the purpose of IR spectroscopy?

The purpose of IR spectroscopy is fundamentally about identifying the molecular structure of compounds by analyzing the functional groups present. When infrared light is passed through a sample, certain wavelengths are absorbed by specific molecular bonds, causing vibrations that correspond to different functional groups. This absorption pattern generates a spectrum that can be interpreted to deduce what functional groups are present in the compound.

The ability of IR spectroscopy to highlight distinct absorption peaks makes it especially powerful for confirming the identity of unknown compounds. Each functional group has characteristic absorption bands, allowing chemists to match the observed spectrum with known spectra to identify the compound or confirm its structure. This application is essential in organic chemistry for both identification and characterization of substances, making it an invaluable tool in laboratory settings.