A saturated solution is a solution which has dissolved as much solute as it can dissolve at a given temperature. If more solutes are added, a saturated solution would not dissolve it. Such solution has reached its carrying capacity.
If the temperature changes, the solution might be able to dissolve more solutes in it.
An undersaturated solution is one in which does not contain enough dissolved solutes in it at a given temperature.
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 .
