ORGANIC CHEMISTRY Chapter 13 13.9A Ultraviolet-Visible Spectroscopy o a uV-Vis spectrophotometer measures the amount of light absorbed at each wavelength of the uv and visible regions of the electromagnetic spectrum o nmaxthe wavelength of maximum absorption o- molar absorptivity C×l Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 13 13.9A Ultraviolet-Visible Spectroscopy A UV-Vis spectrophotometer measures the amount of light absorbed at each wavelength of the UV and visible regions of the electromagnetic spectrum. λmax— the wavelength of maximum absorption. ε — molar absorptivity ε = A C × l