The electronic spectra of organic molecules which are found in UV region (100nm-400nm) and visible region (400nm-750nm) can be studied by the UV-Visible spectrophotometer. UV and Visible radiations absorbed by the molecules will bring transition of outer shell electrons. When the sample is irradiated with the UV - Visible radiation if a particular electronic transition matches the energy of a certain band of UV - Visible, it will be absorbed. The remaining UV - Visible light passes through the sample and is observed with the gaps in the spectrum region and is called absorption spectrum.
· To determine the absorbance or transmission of characteristic wavelengths of radiant energy (light) by a chemical species in solution.
· Identify organic compounds by determining the absorption maximum.
· Used for color determination within the spectral range
· Concentration of impurities
· To study the rate of a reaction