In many experiments, we use IR and/or proton NMR to verify the structure of a compound. Quite often the experiment procedure calls for the use of a drying agent. It is helpful to have a dry sample when obtaining a spectrum because?
1) A dry sample produces a clearer and more accurate spectrum.
2) A dry sample prevents interference from water molecules.
3) A dry sample allows for better resolution of peaks.
4) A dry sample reduces the risk of damage to the equipment.