Each test tube was added with 1 drop of 1% FeCl3 and their reactions was now observed. If only ethanol is used in recrystallization, very large amounts of ethanol would be needed in order to completely dissolve the crystals. This was due majorly for the fact that the filteration system on many of the suction faucets did not work, making for repeated trials while losing parts of product in the process. My melting point for the recrystallized salicylic acid was in a range of 125-130ᵒC, which did not overlap the literature value of 159ᵒF. Add 6 ml of Acetic anhydride to the flask of salicylic acid 3. In many o ccasions, a small amount of mineral acid is used as catalyst to speed up the reaction. A cat alyst is also needed as s alicylic ac id is stabilized by its benzene ring, with lone pairs from the carbonyl gr oup and the hydroxyl group delocalizing with the electrons of the aromatic ring.
Oil of wintergreen was originally produced naturally from the. Overall, the experiment can be deemed as quite successful. The errors made during the experiment will be explained in the discussion section of this report. An organic acid however, is an organic compound which contains acidic properties. This experiment illustrates several properties of organic synthesis. Any traces of water that remain are then removed by a drying agent, either magnesium sulfate or sodium sulfate. Esters are derivatives of organic acids and can be prepared by synthesizing carbox ylic acid and alcohol.
The melting point was 135. Esters are also used commercially as solvents, plasticizers, starting materials for polymers, as well was pharmaceuticals. The water added to get rid of the acetic acid and to wash the crystals must be cold as a cetylsalicy lic acid is soluble in water. Lab 5: Preparation of Synthetic Banana Oil September 20th, 2012 Purpose: The main purpose of this experiment was to synthesize banana oil isopentyl acetate. It also contains information about safety precautions put in place to ensure the safety of the team who carried out the experiment. This was to get rid of the acetic acid by-product, either by dissociation and filtration, or by decomposition. Common properties of esters are fruity smell, pleasant odors and the y are highly volatile.
Finally, allow the crys tals to air dry completely. After 10 minutes, the mixed reagents have been filtered using a vacuum filtration for it to separate the impurities in the Aspirin. Place Erlenmeyer flask containing aspirin and appropriate ethanol in the water bath 20. Only when there action started to cool down did white crystals of acetylsalicylic acid form, as solubility gradually dropped with the reduction in temperature. Phenols, when reacted with FeCl3 inhibit colored complexes, and in this case purple. Methyl Acetate 1 Methanol+ Acetic acid with inorganic acid as catalyst If your experimental yield of aspirin was greater than 100%, how could this occur? The experiment helps demonstrate acyl substitution chemistry while generating student interest in chemistry.
On the other hand, the oil of wintergreen or methylsalicylate also came from the same active ingredient, salicylic acid. Calculate volume of ethanol needed provided 6g of aspirin dissolves in 20 ml of absolute ethanol 18. As a result, the reaction as a whole shifts the left producing more isoamyl acetate to try and balance the reaction once again. The role of inorganic acids in the esterification process is to act as a catalyst; that is to speed up the reaction whilst not being used up itself From what substances can esters be prepared? Why was cold as opposed to warm water used to wash the aspirin you prepared? Repeat filtration process in steps 10-12 23. Preparation and melting point of Aspirin Aspirin is a painkilling drug and is produced worldwide to reduce and stop pain. It is sometimes used to treat or prevent heart attacks, strokes, and angina. By the end of the experiment the target is to produce aspirin as pure as possible.
Write the structural formulas for these esters and name them Methyl EthanoateEthyl Methanoate How would you prepare the two esters above? Calculate the percent yield of acetylsalicylic acid. The process of creating these two esters are also similar in exception to the alcohol added to the salicylic acid carboxylic acid as in both scenarios sulfuric acid an inorganic acid is added to the flask with salicylic acid and the alcohol and said flask is then heated in a water bath. They added ice to the mixture for recrystallization. Conclusion: In the lab, it was apparent that all the students were able to use the air condenser and all other glassware used in the experiment. Esters can be prepared by the reaction of carboxylic acids and alcohols, with an inorganic acid used as a catalyst which is dubbed esterification.
Therefore they are said to be the result of a reaction between a carboxylic acid and an alcohol with water as a side product. All results obtained have been included as well as a detailed analysis of what they represent alongside any improvements to the method used. Furthermore, acetic acid can theoretically react with our product, leading to the production of more unwanted by-products. Hot water on the other hand would further dissolve the aspirin. Materials Lab Equipment 125 ml Erlenmeyer flask 10 ml Graduated cylinder Small watch glass Thermometer Filter paper 600 ml Beaker Large test tubes Hot plate Funnel Chemicals Acetic anhydride 1% Ferric Chloride Solution Salicylic Acid.
From this experiment, yield found to be 46. On performing the FeCl3 test, the collected products were now separated in each test tube. Press crystals between paper towels and allow crystals to air dry Testing Crystals for Purity 13. Hypothesis: The catalyst, glacial acetic acid, will be the most efficient in yielding the purest aspirin because of its chemical properties of C2H4O2. The esterification reaction is reversible, and it has an equilibrium constant of approximately 4.
With o-hydrobenzoic acid, or salicylic acid, we are able to create acetylsalicylic acid otherwise known as aspirin as well as methyl salicylate, which is a component of oil of wintergreen. Salicylic acid and methanol reacts to form methylsalicylate. Heat a beaker of water on the hot plate to 80-90 degrees Celsius, use the thermometer to check temperature 6. SynopsisThe objective of this experiment is to learn to re-crystallise aspirin and to prepare aspirin. After obtaining the white crystals of product, they were then recrystallized with a mixed solvent system of ethanol and water. How would you prepare each of the following? This is a preparation of aspirin and oil of wintergreen lab 1.
Therefore it can be understood that if the aspirin is truly pure, it would not have any trace of salicylic acid as it would be completely reacted and thus have no colour change in the presence of ferric chloride. An ester is an example of being a derivative of these organic acids. This may have been due to a failure to filter out by products and the use of too much water in the process. Introduction An ester is an organic compound formed through the process of esterification, which involves the reaction of an alcohol and an organic acid. Percentage yield was calculated out to find the experimental amount of aspirin formed by esterification of reactants. A single-pot procedure for the preparation of methyl salicylate oil of wintergreen from commercial aspirin tablets has been developed.