Infrared IR spectroscopy is a powerful analytical technique used to identify functional groups in organic compounds. It works by measuring the absorption of infrared radiation by the compound, which causes vibrations in the chemical bonds. Different functional groups have characteristic absorption bands in the IR spectrum, allowing for their identification.Here are some common functional groups and their characteristic IR absorption bands:1. Hydroxyl group OH : Found in alcohols and carboxylic acids, it shows a broad absorption band around 3200-3600 cm.2. Carbonyl group C=O : Present in aldehydes, ketones, carboxylic acids, and esters, it exhibits a strong, sharp absorption band around 1650-1750 cm.3. Amine group NH2 or NH : Found in primary and secondary amines, it shows two or one respectively medium to strong absorption bands in the range of 3300-3500 cm.4. Nitrile group CN : Present in nitriles, it exhibits a medium to strong absorption band around 2210-2260 cm.5. Alkene group C=C : Found in alkenes, it shows a medium to strong absorption band around 1620-1680 cm.6. Alkyne group CC : Present in alkynes, it exhibits a medium to strong absorption band around 2100-2250 cm.7. Aromatic ring C=C in aromatic compounds : Found in aromatic compounds, it shows multiple medium to strong absorption bands in the range of 1400-1600 cm.To identify functional groups in a given organic compound using IR spectroscopy, you would first obtain the IR spectrum of the compound. Then, you would analyze the spectrum to identify the characteristic absorption bands corresponding to the functional groups mentioned above. By comparing the observed absorption bands with the known bands for various functional groups, you can determine which functional groups are present in the compound.