Infrared IR spectroscopy is a powerful analytical technique used to identify functional groups in organic compounds by analyzing the vibrations of molecular bonds. When a molecule absorbs infrared radiation, it causes the bonds within the molecule to vibrate at specific frequencies. These frequencies correspond to the characteristic peaks observed in the IR spectrum.To identify the functional groups present in an unknown organic compound using IR spectroscopy, we need to analyze the characteristic peak frequencies in the spectrum and compare them to known values for various functional groups. Here are some common functional groups and their characteristic peak frequencies:1. Hydroxyl group OH : - Alcohol: Broad peak around 3200-3600 cm- Carboxylic acid: Broad peak around 2500-3300 cm often with a sharp peak around 1700 cm for the carbonyl group 2. Carbonyl group C=O :- Aldehyde: Sharp peak around 1720-1740 cm- Ketone: Sharp peak around 1705-1725 cm- Ester: Sharp peak around 1735-1750 cm- Amide: Sharp peak around 1630-1690 cm3. Amine group NH :- Primary amine: Two peaks around 3300-3500 cm- Secondary amine: One peak around 3300-3400 cm4. Nitrile group CN : Sharp peak around 2210-2260 cm5. Alkene group C=C : Peaks around 1620-1680 cm6. Alkyne group CC : Peaks around 2100-2250 cm usually weak 7. Aromatic ring C=C : Multiple peaks between 1450-1600 cmTo identify the functional groups in the unknown compound, analyze the IR spectrum and look for the characteristic peaks mentioned above. Keep in mind that the presence of multiple functional groups can cause overlapping peaks or shifts in peak frequencies. Additionally, the exact peak frequencies can be influenced by the specific molecular environment and substituents on the molecule.