Infrared IR spectroscopy is a powerful analytical technique used to identify the types of bonds present in a molecule by measuring the absorption of infrared radiation. When a molecule is exposed to infrared radiation, the energy from the radiation causes the bonds within the molecule to vibrate at specific frequencies. These frequencies are characteristic of the type of bond and the atoms involved in the bond. By analyzing the absorption spectrum, chemists can determine the functional groups and types of bonds present in the molecule.For example, let's consider the molecule ethanol C2H5OH . Its IR spectrum would show several characteristic peaks that correspond to the different types of bonds present in the molecule:1. O-H stretch alcohol : A broad peak around 3200-3600 cm-1 indicates the presence of an O-H bond in an alcohol functional group.2. C-H stretch alkane : Peaks in the range of 2800-3000 cm-1 correspond to the C-H stretching vibrations in the alkane portion of the molecule C2H5 .3. C-O stretch ether : A peak around 1000-1300 cm-1 indicates the presence of a C-O bond in an ether functional group.4. C-C stretch alkane : A peak in the range of 800-1200 cm-1 corresponds to the C-C stretching vibrations in the alkane portion of the molecule.By analyzing these peaks in the IR spectrum of ethanol, a chemist can determine the presence of an alcohol functional group O-H , an ether functional group C-O , and alkane functional groups C-H and C-C in the molecule. This information can then be used to confirm the structure of ethanol or to differentiate it from other molecules with similar functional groups.