Final answer:
Gas chromatography is based on the separation of components in a mixture using a stationary phase and a mobile phase. Peaks in the chromatograms can be identified by determining the retention time. The separation efficiency of the column can be analyzed by looking at the peak width.
Step-by-step explanation:
The principle of gas chromatography is based on the separation of components in a mixture using a stationary phase and a mobile phase. The stationary phase is typically a solid or liquid coated on a solid support, and the mobile phase is a gas. The mixture is injected into the column, and as it passes through, the different components interact with the stationary phase to varying degrees, causing them to separate. The separated components are then detected and recorded as peaks on a chromatogram.
Identifying the peaks in the chromatogram involves determining the retention time, which is the time it takes for a component to elute from the column. By comparing the retention times with known standards, the components can be identified. Additionally, the area under each peak can provide information about the relative abundance of each component.
The separation efficiency of the column can be analyzed by looking at the peak width. A narrow peak width indicates a more efficient separation, while a broad peak width indicates poor separation. The retention time of 1-methylcyclohexane can be determined by measuring the time at which the peak for this compound appears on the chromatogram.
The selectivity factor (a) is calculated by dividing the retention time of one peak by the retention time of another peak. The selectivity factors can be compared to the ranking of the chromatograms to see if they agree. If the selectivity factors are consistent with the ranking, it suggests that the separation is working as expected.