Friday, February 20, 2009
Monday, February 16, 2009
Preparation of synthetic banana oil
Purpose of experiment
The purpose of the experiment was to synthesize banana oil known by several chemical names such as isopentyl acetate, isoamyl acetate, and ethanoate using isopentyl alcohol and acetic acid.
Method and procedure
A 20.0mmole of isopentyl alcohol was added to a 5-ml conical vial. About 40mmole of galactic acid was added to the solution, and carefully stirred as six drops of concentrated sulfuric acid was then added. Then the solution was heat under a gentle reflux with a water-cooled condenser for one hour. The solution is then monitored as it reflux and the heat applied to it was reduced from time to time as the reflux rose to about 2cm of the top of the condenser.
After heating, the reaction was cooled to nearly room temperature. Then it was transferred to a screw-cap centrifuge tube with the aid of 6ml of water. The reaction was washed with water, and then the aqueous layer was removed. The organic layer, which was left in the centrifuge tube, was then washed with two portion of about 3ml of 5% aqueous sodium bicarbonate in order to help eliminate the water content. Then the aqueous layer was removed after each washing.
The product, crude isopentyl acetate, was dried with a small amount of anhydrous sodium sulfate. The capped tube was shake vigorously, and let to stand for ten minutes. The sodium sulfates absorbed the water content and formed crystals at the bottom. The liquid was then transferred to a pre-weighed beaker, leaving the anhydrous sodium sulfate in the vial. The obtained product was then weighed and recorded.
Result
The final weight obtained of the product is 1.77g . Because the reactant, both have one to one mole ratio, the theoretical weight predicted from the reaction was
Therefore, the percentage yield of the product is as follows:
Discussion
The final the product obtained was , but the weight was about 68.0% of the theoretical yield which indicated that there might have been a few errors in the experiment. Because the procedure required circumspect handling while synthesizing , the sources of the errors that caused the discrepancy may have been from washing and drying the product. A few part of the organic layer might have been removed in the process of removing the aqueous layer, water or sodium bicarbonate. Another area would have been at the time of drying the product. Too much anhydrous sodium sulfate might have been added because the procedure was not specific as to what quantity should be added.
Conclusion
Isopentyl acetate, the product, was achieved through the method implemented in this experiment. With the use of isopentyl alcohol and acetic acid under the reaction method help to obtain the predicted product. One way this experiment could be developed is to specific precise amount of each compound need to be used in the reaction in order to obtain a better yield of the product.
The purpose of the experiment was to synthesize banana oil known by several chemical names such as isopentyl acetate, isoamyl acetate, and ethanoate using isopentyl alcohol and acetic acid.
Method and procedure
A 20.0mmole of isopentyl alcohol was added to a 5-ml conical vial. About 40mmole of galactic acid was added to the solution, and carefully stirred as six drops of concentrated sulfuric acid was then added. Then the solution was heat under a gentle reflux with a water-cooled condenser for one hour. The solution is then monitored as it reflux and the heat applied to it was reduced from time to time as the reflux rose to about 2cm of the top of the condenser.
After heating, the reaction was cooled to nearly room temperature. Then it was transferred to a screw-cap centrifuge tube with the aid of 6ml of water. The reaction was washed with water, and then the aqueous layer was removed. The organic layer, which was left in the centrifuge tube, was then washed with two portion of about 3ml of 5% aqueous sodium bicarbonate in order to help eliminate the water content. Then the aqueous layer was removed after each washing.
The product, crude isopentyl acetate, was dried with a small amount of anhydrous sodium sulfate. The capped tube was shake vigorously, and let to stand for ten minutes. The sodium sulfates absorbed the water content and formed crystals at the bottom. The liquid was then transferred to a pre-weighed beaker, leaving the anhydrous sodium sulfate in the vial. The obtained product was then weighed and recorded.
Result
The final weight obtained of the product is 1.77g . Because the reactant, both have one to one mole ratio, the theoretical weight predicted from the reaction was
Therefore, the percentage yield of the product is as follows:
Discussion
The final the product obtained was , but the weight was about 68.0% of the theoretical yield which indicated that there might have been a few errors in the experiment. Because the procedure required circumspect handling while synthesizing , the sources of the errors that caused the discrepancy may have been from washing and drying the product. A few part of the organic layer might have been removed in the process of removing the aqueous layer, water or sodium bicarbonate. Another area would have been at the time of drying the product. Too much anhydrous sodium sulfate might have been added because the procedure was not specific as to what quantity should be added.
Conclusion
Isopentyl acetate, the product, was achieved through the method implemented in this experiment. With the use of isopentyl alcohol and acetic acid under the reaction method help to obtain the predicted product. One way this experiment could be developed is to specific precise amount of each compound need to be used in the reaction in order to obtain a better yield of the product.
Identification of a Conjugated Diene from Eucalyptus Oil
Purpose of Experiment
The purpose of this experiment was identify an unknown conjugated diene from Eucalyptus Oil. Diel-Alder adduct of the unknown conjugated is prepared in Eucalyptus oil , separated and identified using the melting point of the adduct. The reaction carried out in this experiment is as follows :
Methods and proceduce
Into a 5-ml conical vial, 1.00g of eucalptus oil was dissolved in 2.0ml of anhydrous ethyl ether. Then 0.360g of powdered maleic anhydride was added. The reaction was then heated using a cooled condenser for under a gentle reflux at about sixty degrees forty-five minutes.
After the reaction was over, the mixture was let to cool to room temperature. Crystals formed in the vial as the mixture cooled. When crystallization was almost complete, the vial was then cooled in an ice bath for a few minutes to allow more formation of cryatals.
The adduct was collected by vaccum filteration with 1.5ml of cold, low-boiling point ether used to wash the cystals off the vial. The adduct was then recystallized from dry methanol just immediately the methanol began to boil. The adduct was dried and measured. The melting point of the adduct was also recorded and used to deduce the identity of the eucalyptus oil diene.
Results
The weight of the product from the experiment was 0.47g, and the melting point obtained fell in the range of 107°C-112°C. Therefore, the conjugated diene was α-phellandrene, which has a melting point between 126°C-127°C, because it has a melting point which is closer to that of the unknown.
Below is the percent yield of the product obtained :
(1g oil 50% eucalyptus oil )/(136.2g/mol) = 0.00367mole of eucalyptus oil
Because euclyptus oil and the unknown compound are in 1:1 mole ratio, 0.00367mole of unknown compound (α-phellandrene) will be obtained.
Actual of α-phellandrene = 0.47grams
Theoretical of α-phellandrene = 0.00367moles x molecular weight of α-phellandrene = Mgrams
Percentage yield = (0.47g )/Mg x 100%=Y%
Discussion
The yield obtained from the experiment was 94.0% of the actual yield. Possible sources led to the error in the results. Some of the product might have been lost in the process of vacuum filteration. This lead to few crystals been obtained as product, and decreased the weight. The reaction took longer time to react because the stirring bar did not properly stirr the solution. It might have also lead to less yield of product.
The melting point obtained from the solution was between 107°C-112°C , and differed from the actual melting point by 15°C-19°C. The discrepancy in the result might have been from the equipment used. The solution was inserted into the melting point apparatus while it was warm (about 60°C). This might have led to the lower boiling point obtained as supposed to that of α-phellandrene, which is between 126°C-127°C.
The method of characterization used in this experiment supports purity of the product obtained. The product was much like the hypothesized diene. The physical features such as color, which was white, melting point, melting point, texture and so on are similar to that of α-phellandrene.
Conclusion
The purpose of the experiment was to identify an unknown diene using the Diels-Alder reaction. The objective and purpose of the experiment was obatined with the method that was implemented to purify the product. One way this experiment could be improved is to strictly follow the procedures of the experiment, and avoid taking the melting point with a melting point apparatus that is not at room temperature.
The purpose of this experiment was identify an unknown conjugated diene from Eucalyptus Oil. Diel-Alder adduct of the unknown conjugated is prepared in Eucalyptus oil , separated and identified using the melting point of the adduct. The reaction carried out in this experiment is as follows :
Methods and proceduce
Into a 5-ml conical vial, 1.00g of eucalptus oil was dissolved in 2.0ml of anhydrous ethyl ether. Then 0.360g of powdered maleic anhydride was added. The reaction was then heated using a cooled condenser for under a gentle reflux at about sixty degrees forty-five minutes.
After the reaction was over, the mixture was let to cool to room temperature. Crystals formed in the vial as the mixture cooled. When crystallization was almost complete, the vial was then cooled in an ice bath for a few minutes to allow more formation of cryatals.
The adduct was collected by vaccum filteration with 1.5ml of cold, low-boiling point ether used to wash the cystals off the vial. The adduct was then recystallized from dry methanol just immediately the methanol began to boil. The adduct was dried and measured. The melting point of the adduct was also recorded and used to deduce the identity of the eucalyptus oil diene.
Results
The weight of the product from the experiment was 0.47g, and the melting point obtained fell in the range of 107°C-112°C. Therefore, the conjugated diene was α-phellandrene, which has a melting point between 126°C-127°C, because it has a melting point which is closer to that of the unknown.
Below is the percent yield of the product obtained :
(1g oil 50% eucalyptus oil )/(136.2g/mol) = 0.00367mole of eucalyptus oil
Because euclyptus oil and the unknown compound are in 1:1 mole ratio, 0.00367mole of unknown compound (α-phellandrene) will be obtained.
Actual of α-phellandrene = 0.47grams
Theoretical of α-phellandrene = 0.00367moles x molecular weight of α-phellandrene = Mgrams
Percentage yield = (0.47g )/Mg x 100%=Y%
Discussion
The yield obtained from the experiment was 94.0% of the actual yield. Possible sources led to the error in the results. Some of the product might have been lost in the process of vacuum filteration. This lead to few crystals been obtained as product, and decreased the weight. The reaction took longer time to react because the stirring bar did not properly stirr the solution. It might have also lead to less yield of product.
The melting point obtained from the solution was between 107°C-112°C , and differed from the actual melting point by 15°C-19°C. The discrepancy in the result might have been from the equipment used. The solution was inserted into the melting point apparatus while it was warm (about 60°C). This might have led to the lower boiling point obtained as supposed to that of α-phellandrene, which is between 126°C-127°C.
The method of characterization used in this experiment supports purity of the product obtained. The product was much like the hypothesized diene. The physical features such as color, which was white, melting point, melting point, texture and so on are similar to that of α-phellandrene.
Conclusion
The purpose of the experiment was to identify an unknown diene using the Diels-Alder reaction. The objective and purpose of the experiment was obatined with the method that was implemented to purify the product. One way this experiment could be improved is to strictly follow the procedures of the experiment, and avoid taking the melting point with a melting point apparatus that is not at room temperature.
Learning to use the Fourier transform infrared spectroscopy (FT-IR)
Purpose of Experiment
The purpose of this experiment was identify an unknown compound using the Fourier transform infrared spectroscopy (FT-IR).
Methods and proceduce
Fourier transform infrared spectroscopy (FT-IR) was used to take the absorbance of the unknown solution. A graph of the results from the spectroscopy was plotted, and used to determine the organic substance. A correlation factor was also obtained from the FT-IR.
Results
The correlation factor obtained was 0.963274, which showed that the mostly likely compound is benzaldehyde from the FT-IR spectrometer and the graph obtained
structure of benzaldehyde
Discussion
The solution is benzaldehyde because the graph plotted showed a C=O strong spike at about 1700, and an indication of benzene ring at about 1600. On the graph, there was an O=H spike at about 3300. Also, the presence of two spikes between 2700 and 2900 indication the presence of an aldehyde as seen in the structure of benzaldehyde. These featured proved that the compound was truly benzaldehyde because the graph obtained showed a lot similarity to that of benzaldehyde.
Conclusion
The purpose of the experiment, which was to identify the unknown compound using the FT-IR spectroscopy, was achieved because the graph showed features which proved that the correlation molecule benzaldehyde was contained in the unknown.
The purpose of this experiment was identify an unknown compound using the Fourier transform infrared spectroscopy (FT-IR).
Methods and proceduce
Fourier transform infrared spectroscopy (FT-IR) was used to take the absorbance of the unknown solution. A graph of the results from the spectroscopy was plotted, and used to determine the organic substance. A correlation factor was also obtained from the FT-IR.
Results
The correlation factor obtained was 0.963274, which showed that the mostly likely compound is benzaldehyde from the FT-IR spectrometer and the graph obtained
structure of benzaldehyde
Discussion
The solution is benzaldehyde because the graph plotted showed a C=O strong spike at about 1700, and an indication of benzene ring at about 1600. On the graph, there was an O=H spike at about 3300. Also, the presence of two spikes between 2700 and 2900 indication the presence of an aldehyde as seen in the structure of benzaldehyde. These featured proved that the compound was truly benzaldehyde because the graph obtained showed a lot similarity to that of benzaldehyde.
Conclusion
The purpose of the experiment, which was to identify the unknown compound using the FT-IR spectroscopy, was achieved because the graph showed features which proved that the correlation molecule benzaldehyde was contained in the unknown.
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