For typical analysis of thin layer chromatography, a quick simple way to check for compounds is to use UV/Vis. Most lamps have both a long and short wavelength setting, which are at 254nm and 365nm respectively. For the following compounds, indicate whether you think that they would appear (be visible, ie absorb) at one or both of those wavelengths. 2. Reactions can also often be monitored using UV/Vis spectroscopy, by significant changes in absorption wavelength. For the following reactions, indicate whether you think that they could be easily followed by UV/Vis or not, and indicate what difference you would expect to see (if any). Na3 PCC Pdic H2SO4