Introduction
The purpose of this experiment was to purify a solution of two unknown volatile compounds with different boiling points into its separate components through fractional distillation. The unknowns were selected from a possible list of seven unknowns with boiling points and retention times provided (see data and results). By observing the volume of the distillates produced by this process and the vapor temperature, the boiling point of the two different compounds was determined. The secondary purpose of this experiment was to ascertain the identity of the unknowns by using gas chromatography (GC) to determine the retention time of the compounds. The fractional distillation apparatus used in this experiment was prepared following …show more content…
Comparing to the provided retention times for Acetone (0.64) and Toluene (0.87) the speculative identities for the unknowns based off the boiling points were correct. The GC also provided the percent composition for all three fractions from which the ratio of low to high unknowns in mixture was able to be calculated as 47.34% Acetone : 52.67% Toluene (calculations in lab notebook). In addition, the individual fraction GC percentages show amounts up to 20% of the non primarily boiling solution (at the time of fraction), this means that the the temperature gradient was not successfully implemented in the fractional distillation system therefore leading to uneven heating of solution which lead to a decreased quality of isolation. The class ratio was: 51.1% Acetone : 48.9 % Toluene; and the actual ratio of the stock solution was 30.8 % Acetone : 69.2 % Toluene. As previously discussed there actually was a consequence of failing to properly observe the plateau- the percentage of Acetone in solution, compared to the actual ratio, was overestimated because Toluene was not allowed to fully distill. The class average also sees an overestimation of Acetone percentage but at a higher magnitude (47.34% personal to 51.1% class), the difference between these too is relatively small but compared to the actual solution percentage the differences are much more exaggerated. The class average should have been closer to stock because it allows for errors in both direction (towards Toluene and towards Acetone) to average out. Since the class skews towards Acetone similarly, the same mistake of prematurely switching from fraction B to C could be at fault. But a simpler source of error may be at fault- the covering of the system, might the temperature gradient was not properly achieved, because the system was not properly covered with cotton and aluminum,
The purpose of this experiment was to purify a solution of two unknown volatile compounds with different boiling points into its separate components through fractional distillation. The unknowns were selected from a possible list of seven unknowns with boiling points and retention times provided (see data and results). By observing the volume of the distillates produced by this process and the vapor temperature, the boiling point of the two different compounds was determined. The secondary purpose of this experiment was to ascertain the identity of the unknowns by using gas chromatography (GC) to determine the retention time of the compounds. The fractional distillation apparatus used in this experiment was prepared following …show more content…
Comparing to the provided retention times for Acetone (0.64) and Toluene (0.87) the speculative identities for the unknowns based off the boiling points were correct. The GC also provided the percent composition for all three fractions from which the ratio of low to high unknowns in mixture was able to be calculated as 47.34% Acetone : 52.67% Toluene (calculations in lab notebook). In addition, the individual fraction GC percentages show amounts up to 20% of the non primarily boiling solution (at the time of fraction), this means that the the temperature gradient was not successfully implemented in the fractional distillation system therefore leading to uneven heating of solution which lead to a decreased quality of isolation. The class ratio was: 51.1% Acetone : 48.9 % Toluene; and the actual ratio of the stock solution was 30.8 % Acetone : 69.2 % Toluene. As previously discussed there actually was a consequence of failing to properly observe the plateau- the percentage of Acetone in solution, compared to the actual ratio, was overestimated because Toluene was not allowed to fully distill. The class average also sees an overestimation of Acetone percentage but at a higher magnitude (47.34% personal to 51.1% class), the difference between these too is relatively small but compared to the actual solution percentage the differences are much more exaggerated. The class average should have been closer to stock because it allows for errors in both direction (towards Toluene and towards Acetone) to average out. Since the class skews towards Acetone similarly, the same mistake of prematurely switching from fraction B to C could be at fault. But a simpler source of error may be at fault- the covering of the system, might the temperature gradient was not properly achieved, because the system was not properly covered with cotton and aluminum,