Previously, for the first part of the experiment, it was hypothesized that the retention times of the eluates were invariably associated with the polarity of the compound; the more non-polar the compound, the faster it would be eluted out of the gas chromatogram. It was also hypothesized that the retention times decreased as the temperature in the gas column increased. In the first part of the experiment the relationship between the temperature and retention time, and the non-polarity of the molecule and the retention time was determined. As the temperature in the gas column increased the organic compounds eluted out of the gas chromatogram with a shorter retention time.
When the temperatures are higher than the organic compound’s boiling …show more content…
Through this lab, we acknowledged how polarity, boiling point, bonding functional groups of a compound determine the retention time, the time it takes form the molecule to be eluted. As the hydrophobic interactions increase between the mobile phase and the stationary phase of the gas column, the retention time increases, the more non-polar substances spend time in the gas chromatograph for a longer time. Boiling point also plays a major factor in how fast the eluates are ejected from the gas column. Also in this experiment, we learned how to calculate the thermodynamic parameters with the measured retention times. From the graphs it was evident that in a condensation process: reaction releases energy (-ΔH°), becomes more ordered (-ΔS°) and is spontaneous (-ΔG°) at low temperatures. Moreover, through this experiment we noticed that the stronger the hydrophobic interactions between two compounds are, it releases more energy, is less ordered, and is more spontaneous; more non-polar atoms had a stronger hydrophobic interaction with the non-polar surface of the gas column (Table 7). Hence, the purpose of this experiment was justified as we found the correlation between the retention times of the eluates and the thermodynamic components of the hydrophobic interaction between the stationary and mobile
When the temperatures are higher than the organic compound’s boiling …show more content…
Through this lab, we acknowledged how polarity, boiling point, bonding functional groups of a compound determine the retention time, the time it takes form the molecule to be eluted. As the hydrophobic interactions increase between the mobile phase and the stationary phase of the gas column, the retention time increases, the more non-polar substances spend time in the gas chromatograph for a longer time. Boiling point also plays a major factor in how fast the eluates are ejected from the gas column. Also in this experiment, we learned how to calculate the thermodynamic parameters with the measured retention times. From the graphs it was evident that in a condensation process: reaction releases energy (-ΔH°), becomes more ordered (-ΔS°) and is spontaneous (-ΔG°) at low temperatures. Moreover, through this experiment we noticed that the stronger the hydrophobic interactions between two compounds are, it releases more energy, is less ordered, and is more spontaneous; more non-polar atoms had a stronger hydrophobic interaction with the non-polar surface of the gas column (Table 7). Hence, the purpose of this experiment was justified as we found the correlation between the retention times of the eluates and the thermodynamic components of the hydrophobic interaction between the stationary and mobile