Steam Distillation
Discussion:
The purpose of this experiment was to isolate the aromatic hydroxyl compound, eugenol from crushed cloves using steam distillation. After conducting the distillation, the expected two layers were not visible in the centrifuge tube. Subsequently, the extraction and evaporation did not produce the expected oil. This result is probably due to the collection of only water vapor during distillation.
From another group’s data, 3.80% of the oil was recovered from the cloves in which the major component is eugenol. The IR spectrum obtained is consistent with the structure of eugenol. In addition, the IR of the product from the steam distillation of the cloves closely corresponds with that of an authentic sample of eugenol shown in the lab manual (pg.69). Thus, it can be concluded that the oil obtained from the cloves is in fact eugenol.
Source of Error:
1) The distillation rate may have been too fast which could lead to the collection of a less pure distillate, and subsequently a higher percent recovery than the actual value
Conclusion:
In this experiment, it was shown that about 3.8% of oil could be recovered from cloves by steam distillation. This oil was identified as eugenol by comparison of its infrared spectrum with an authentic sample.
Post Lab Questions:
1) Steam distillation is used to isolate eugenol rather than simple distillation because the boiling point of eugenol is 250°C, which means the compound would most likely decompose if it were distilled directly. Eugenol is also immiscible with water.
2)
a) Mass of the oil that co-distills with each one gram of water at 98 °C:
Ptotal = 1 atm = 760 mmHg P°water (98 °C) = 707.3 mmHg
P°oil = 760 mmHg – 707.3 mmHg = 52.7 mmHg
1 g H2O x (1 mol H2O)/(18 g H2O) = 0.06 mol H2O
P°oil / P°water = moles (oil) / moles (water)
(52.7 mmHg) / (707.3 mmHg) = moles (oil) / (0.06 mol H2O)
=> moles (oil) = 0.00417 mol 0.00417 mol oil x (169 g oil)/(1 mol oil) = 0.705 g oil
b)
The purpose of this experiment was to isolate the aromatic hydroxyl compound, eugenol from crushed cloves using steam distillation. After conducting the distillation, the expected two layers were not visible in the centrifuge tube. Subsequently, the extraction and evaporation did not produce the expected oil. This result is probably due to the collection of only water vapor during distillation.
From another group’s data, 3.80% of the oil was recovered from the cloves in which the major component is eugenol. The IR spectrum obtained is consistent with the structure of eugenol. In addition, the IR of the product from the steam distillation of the cloves closely corresponds with that of an authentic sample of eugenol shown in the lab manual (pg.69). Thus, it can be concluded that the oil obtained from the cloves is in fact eugenol.
Source of Error:
1) The distillation rate may have been too fast which could lead to the collection of a less pure distillate, and subsequently a higher percent recovery than the actual value
Conclusion:
In this experiment, it was shown that about 3.8% of oil could be recovered from cloves by steam distillation. This oil was identified as eugenol by comparison of its infrared spectrum with an authentic sample.
Post Lab Questions:
1) Steam distillation is used to isolate eugenol rather than simple distillation because the boiling point of eugenol is 250°C, which means the compound would most likely decompose if it were distilled directly. Eugenol is also immiscible with water.
2)
a) Mass of the oil that co-distills with each one gram of water at 98 °C:
Ptotal = 1 atm = 760 mmHg P°water (98 °C) = 707.3 mmHg
P°oil = 760 mmHg – 707.3 mmHg = 52.7 mmHg
1 g H2O x (1 mol H2O)/(18 g H2O) = 0.06 mol H2O
P°oil / P°water = moles (oil) / moles (water)
(52.7 mmHg) / (707.3 mmHg) = moles (oil) / (0.06 mol H2O)
=> moles (oil) = 0.00417 mol 0.00417 mol oil x (169 g oil)/(1 mol oil) = 0.705 g oil
b)