Describe6 marksChallenge
A reaction mixture is analysed by gas–liquid chromatography using a non-polar stationary phase and nitrogen as the mobile phase. The chromatogram shows two peaks, P and Q. Peak P appears at a retention time of 2.5 minutes and peak Q at 8.0 minutes. The areas under the peaks are proportional to the amount of each substance present. The mixture is known to contain two compounds, X and Y, of similar molar mass. Compound X is non-polar; compound Y is polar.
Describe how this chromatogram allows the mixture to be separated and analysed. In your answer, refer to the stationary phase, the mobile phase, the retention times of P and Q, and the information that can be obtained about the composition of the mixture.