Infrared IR spectroscopy is a powerful analytical technique used to identify the presence of functional groups in a given compound. It works by measuring the absorption of infrared radiation by the compound, which causes vibrational transitions in the molecular bonds. Different functional groups have characteristic vibrational frequencies, which can be observed as distinct peaks in the IR spectrum.To identify the presence of a particular functional group in a compound using IR spectroscopy, follow these steps:1. Obtain the IR spectrum of the compound by exposing it to a range of infrared radiation frequencies. The compound will absorb specific frequencies corresponding to the vibrational transitions of its molecular bonds.2. Analyze the spectrum by looking for characteristic peaks or bands that correspond to the functional group of interest. These peaks appear at specific frequency ranges, which are unique to each functional group.3. Compare the observed peaks in the spectrum to a reference table or database of known functional group frequencies. If the observed peaks match the characteristic frequencies of the functional group, it is likely present in the compound.Here are some common functional groups and their corresponding frequency ranges in the IR spectrum in cm :- Hydroxyl group O-H : 3200-3600 broad peak - Carboxylic acid O-H : 2500-3300 broad peak - Amine N-H : 3300-3500 sharp peak - Alkene C=C : 1620-1680- Alkyne CC : 2100-2260- Carbonyl C=O : - Aldehyde: 1720-1740 - Ketone: 1705-1725 - Ester: 1735-1750 - Carboxylic acid: 1700-1720 - Amide: 1630-1690Keep in mind that these frequency ranges are approximate and can vary depending on the specific compound and its environment. Additionally, some functional groups may have overlapping frequency ranges, so it is essential to consider the entire spectrum and other available information when identifying functional groups.