Question

How is infrared spectroscopy used to identify compounds?

Answer 1

Hint: Infrared spectroscopy can be defined as the measurement of the interaction of the infrared radiation with the matter by absorption, emission or the reflection. The method or the technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer in which it produces infrared spectrum.

Complete answer:
First of all the IR (infrared) frequency light is passed through the compound and accordingly the amount and the frequency of the light absorbed relates and identifies the functional groups and the structure of the compound and which ultimately helps us to identify the compound.
Infrared spectroscopy methods use the light wavelengths from the infrared to ultraviolet. The used wavelength will correspond to the different characteristics of the molecules and the atoms.
In organic chemistry the infrared spectroscopy is most frequently used to identify the chemical structures, composition from the characteristic absorption of IR (infrared) light by the different organic functional groups. Thus, the presence of the hydroxyl groups, double bonds and the other active parts of the molecule can be deduced.
The vibrating bonds in the functional groups absorb the energy at the frequency which corresponds to the vibrational frequency of the bond and makes infrared spectroscopy useful for identifying the functional groups of the molecule.

Note :
Infrared spectroscopy is used to study and identify chemical substances or the functional groups in any form such as solid, liquid or gaseous. The common laboratory instrument which uses this technique is the Fourier transform infrared spectrum.