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What functional groups can be identified using infrared (IR) spectroscopy? Provide an example of an IR spectrum and explain how it can be used to identify the functional group present in a compound.

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Infrared  IR  spectroscopy is a powerful analytical technique used to identify various functional groups in organic compounds by analyzing the absorption of infrared radiation by the molecules. When a molecule absorbs infrared radiation, it causes the bonds within the molecule to vibrate at specific frequencies, which are characteristic of the functional groups present in the compound.Some common functional groups that can be identified using IR spectroscopy include:1. Hydroxyl group  OH  - found in alcohols and carboxylic acids2. Carbonyl group  C=O  - found in aldehydes, ketones, carboxylic acids, and esters3. Amine group  NH2, NH, N  - found in primary, secondary, and tertiary amines4. Nitrile group  CN  - found in nitriles5. Alkene group  C=C  - found in alkenes6. Alkyne group  CC  - found in alkynes7. Aromatic ring  C=C  - found in aromatic compoundsExample of an IR spectrum:Suppose we have an IR spectrum of an unknown compound with the following significant absorption bands:1. 3300 cm  broad and strong 2. 1710 cm  sharp and strong 3. 1050 cm  medium To identify the functional groups present in the compound, we can analyze these absorption bands:1. The broad and strong absorption at 3300 cm is characteristic of the hydroxyl group  OH  found in alcohols and carboxylic acids.2. The sharp and strong absorption at 1710 cm is indicative of a carbonyl group  C=O  found in aldehydes, ketones, carboxylic acids, and esters.3. The medium absorption at 1050 cm can be attributed to the C-O single bond, which is present in alcohols, carboxylic acids, and esters.Based on this information, we can conclude that the compound contains both a hydroxyl group  OH  and a carbonyl group  C=O , along with a C-O single bond. This suggests that the compound is likely a carboxylic acid, as carboxylic acids contain both hydroxyl and carbonyl functional groups.

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