Infrared IR spectroscopy is a powerful analytical technique used to identify functional groups in organic compounds by analyzing their characteristic absorption peaks. When a molecule absorbs infrared radiation, it causes the bonds within the molecule to vibrate at specific frequencies. These frequencies are unique to the type of bond and functional group present in the molecule.To identify the functional groups present in an unknown compound using IR spectroscopy, you should follow these steps:1. Obtain the IR spectrum of the unknown compound. This will show the absorption peaks at various frequencies measured in wavenumbers, cm .2. Analyze the spectrum and look for characteristic absorption peaks that correspond to specific functional groups. Some common functional groups and their characteristic IR absorption peaks are: a. Hydroxyl group O-H : Broad peak around 3200-3600 cm alcohols, phenols, and carboxylic acids b. Carbonyl group C=O : Sharp peak around 1650-1750 cm aldehydes, ketones, esters, and carboxylic acids c. Amine group N-H : Medium to broad peak around 3300-3500 cm primary and secondary amines d. Nitrile group CN : Sharp peak around 2210-2260 cm e. Alkene group C=C : Peak around 1620-1680 cm f. Alkyne group CC : Peak around 2100-2250 cm g. Aromatic ring C=C : Multiple peaks around 1450-1600 cm3. Compare the observed peaks in the unknown compound's IR spectrum to the characteristic peaks of known functional groups. If a peak matches the characteristic peak of a functional group, it is likely that the functional group is present in the compound.4. Keep in mind that some functional groups may have overlapping peaks or may be influenced by neighboring functional groups. In such cases, additional analytical techniques e.g., NMR spectroscopy may be necessary to confirm the presence of specific functional groups.By following these steps and comparing the IR spectrum of the unknown compound to the characteristic absorption peaks of known functional groups, you can identify the functional groups present in the compound.