Name 2 separate problems that occur when a sample for infrared analysis is contaminated with water.

The water molecules gets trapped in the crystal structure to be analysed and will give a peak in the spectra at about 3500 / cm, and there by hindering with the IR spectra of the sample to be analysed. The second problem with the contamination of the sample with water is, that water makes the potassium bromide disc opaque which will decrease the absorption of the IR by the sample.