represents the additional driving force required to overcome barriers such as the large activation energy for the formation of a gas at a metal surface.
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 .