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Data and observations obtained during the experiment in recrystallization
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Synopsis The general objective of this experiment was for the students to familiarise with the preparation of a simple organic compound and to purify the compound by recrystallization. This experiment allows the students to conduct synthesis of aspirin, reinforcing the skills of recrystallization and the technique of melting point determination. Esterification was used to synthesize aspirin which was by reacting salicylic acid with acetic anhydride. To speed up the reaction, dehydrating agent and conc. sulphuric acid was present. The purity of a substance, which is the aspirin in this particular experiment, can be determined by the identification of its melting point. Both experimental successes and errors were analysed. The mass of aspirin …show more content…
The aspirin crystals were packed into 3 small capillary tubes to ensure that they are compressed so as to prevent any air gaps. Subsequently, the aspirin crystals that are in the 3 capillary tubes are placed into the melting apparatus and the temperature range was recorded. Since the range is quite far from the theoretical value of 140°C, aspirin's purity attained was low due to impurities present. One potential reason is because of the swift cooling. When the aspirin is left to cool, the crystal lattices will form too rapidly which will surround other molecules thus making the aspirin impure. Another reason could be because the recrystallized aspirin has not dry completely and there might me left over solvent that will affect the temperature range of the aspirin. From the both derived calculations, the aspirin obtained is relatively pure. This result could be due to possible experimental errors or inaccurate techniques performed which led to a percent yield that is not up to expectation. Furthermore, the reaction might not have been completely reacted or the salicylic acid in the solution of acetic anhydride and concentrated sulphuric acid did not dissolve completely when it was being heated. These factors might affect the overall results of the aspirin yield
Extraction is a separation method that is often used in the laboratory to separate one or more components from a mixture. Sucrose was separated at the beginning because it is the most immiscible and it’s strongly insoluble. Next Acetylsalicylic Acid was separated which left Acetanilide alone. Variety steps could have led to errors occurring. For example the step of separation, when dichloromethane layer was supposed to be drained out, it could be possible some aqueous layer was drained with it. Which could make the end result not as accurate. Also errors could have occurred if possibly some dichloromethane was not drained out. Both way could interfere with end result of figuring the amount of each component in the mixture. The solids percentage were 22.1% more than the original. That suggests that solids weren’t separated completely which clarifies the reason the melting points that were recorded were a slightly lower than the actual component’s melting point. The melting point for Acetylsalicylic Acid is 136 C but that range that was recorded during the experiment was around 105 C to 118 C. The melting points were slightly lower than the literature value. Sucrose was the purest among all component due to its higher melting point which follows the chemical rule that the higher the melting point the more pure the component
In the first section, the Synthesis of Aspirin, salicylic acid was weight to be 3.029 grams using mass by difference since it was weighed on a 150 milliliter beaker. 9.23 milliliters of the acetic anhydride and 14 drops of 85 percent phosphoric acid were added to this beaker. A Bunsen burner provided by the laboratory was then used to boil the just mixed combination by producing a flame underneath the positioned beaker on top, and then allowed to cool for several minutes after the Bunsen burner flame was terminated. Two quantities of distilled water were then added to this mixture to make it cool even further, which were 41 drops and 30 milliliters. After cooling for some time, this beaker was placed into an ice bath in order to start the crystallization process. A glass rod was used to scratch around the bottom and the sides to catch all of the crystallized Aspirin that was being formed during this whole process. Then, by using a Buchner funnel and filter paper, which was placed on top of the flask connected to a water aspirator with rubber tubing, the excess liquid was removed from the just scraped Aspirin crystals when the Aspirin was placed on the filter paper. Using a medicine dropper, the Aspirin crystals on the filter paper were washed with distilled water just so that any non-pure substances were removed from the crude product. When these crystals were then ultimately dry, they were placed on a watch glass and put into an oven for 30 minutes. Then they were weighed by mass by difference to yield 2.4667 grams of crude s...
Looking at my results, I can see that I only obtained 86.6% of aspirin. this is not the highest percentage that it could be. I probably lost some aspirin when I had to re-filtered the solution multiple times, or when I had to weigh a new beaker and maybe not all of it got transferred over to the new beaker, or maybe I didn’t get all of the aspirin crystals off of the paper towel and into the beaker. Regardless, of where the aspirin sample was lost, I obtained a 86.6% of aspirin from this
Aspirin is also known as Acetylsalicylic acid. It is composed of nine Carbon atoms, eight Hydrogen atoms, and four Oxygen atoms. There are many chemical properties to it. The melting point of aspirin is about one hundred and thirty-five degrees Celsius and the boiling point is one hundred and forty degrees Celsius. It has a density of 1.35 grams per milliliter and the molar mass is 180,160 g/mol (1). This means that the molecule is relatively dense. There is more weight than there is volume. Aspirin is described as odorless and colorless to where the color is white. It looks like a crystal-line powder at room temperature. It is a relatively stable molecule that should be stored at room temperature (2).
The purpose of this experiment was to study the reactions of amino acids and aspartame. Several solutions were prepared and used in TLC analysis. A permanganate test and a ceric nitrate test were also performed. The summary of the results is shown below.
The purpose of conducting this experiment was to synthesise and characterise for the preparation of benzocaine via a fishcer esterification reaction by the means of amino benzoic acid alongside ethanol. The product was also precipitated from a solution in order to gain a pH of 8.The secondary aim was to esterify the reaction in an equilibrium reaction catalysed via the addition of acid shown below:
Aspartame or known by its chemical formula of C14H18N2O5, is a very common chemical food additive usually added in artificial sweeteners for coffee and other products like Splenda and Equal. It is also mixed with other food products like candy, gum, vitamins and supplements. Its molar mass is 294 grams per mol or it has 294 as its molecular mass. Its chemical structure forms a dipeptide-methyl ester (Walters, 2001). Aspartame is known as a synthetic chemical combination which is built approximately on phenylalanine, aspartic acid and methanol (Wells, 2011). It is a solid and can dissolve with water (Walters (2)). It is chemically manufactured by using tritylation and chlorination ("Chemical Process Steps," n.d.). But when its manufacturing process is discussed, its patent reveals that it uses by-products of genetically-modified cells and later treated with chemicals and methanol to produce aspartame (Butler, 2013).
Aspirin (acetylsalicylic acid) is a type of acid categorized as a salicylate, this acid works as a pain reliever in the body because once digested it lowers the amount of substances already in the body that cause pains, fevers and flare ups. Also, this chemical is administered to people for prevention of heart attacks, strokes, and angina which is also known as severe chest pains. Aspirin is created by chemically synthesizing salicylic acid through the acetylation with acetic anhydride, synthesizing aspirin comprises of three steps, synthesis of it, isolation and purification of it, and testing the purity of the aspirin made. Synthesizing aspirin is done by reacting salicylic acid and acetic anhydride with a catalyst, in which phosphoric acid (H3PO4) is used. After the aspirin has been prepared (synthesized), it must be isolated and purified. Aspirin is insoluble in cold water, therefore it can be isolated by filtering the cold solution product of the reaction. In order to remove the unreacted salicylic acid, acetic anhydride, acetic acid product and phosphoric acid the solution must be purified, the acetic anhydride is decomposed simply through the use of adding water after the reaction has finished (C4H602 + H20 2C2H402). Acetic acid and phosphoric acid can be removed from the solution by soaking the aspirin in cold water since they are soluble in water. The final ending step of purifying the aspirin is through a process referred to as recrystallization. This is when the aspirin is placed in warm ethanol, the solution is cooled, and the aspirin crystallizes leaving the salicylic acid and other impurities inside the solution. Lastly testing the purity of the finished product is achieved mainly from a melting point test a common...
Part 4 of this lab showed a way to observe impurities by comparing the melting point of crude and pure samples. Since impurities are to be shown in the crude sample it would have a lower melting point and larger range. The known melting point of aspirin is to be 135 oC. The crude sample had a melting point range from 69oC to 81 oC. While the Pure sample melting point range was from 116oC to 125oC. Since the Pure sample was still below 135 oC, this shows that there are still some impurities
Organic compounds are naturally permeated with impurities that can possibly pose problems in organic synthesis reactions. Therefore, an important part of organic chemistry lab is in the purification of substances. Unit three was a technique experiment in distillation, and its purpose was in the introduction of two types of distillation methods, although there are various other types. The main purpose of the lab was learning how to distinguish the appropriate time to use either of the distillation methods and learning how to interpret the analysis tools employed to determine the purity of a distillate. The first week of the unit separated acetone and ethanol via the fractional distillation method, while the second week separated the acetone
Analysis of Aspirin Tablets Aim --- To discover the percentage of acetylsalicylic acid in a sample of aspirin tablets. ----------------------------------------------------------------- In order to do this, the amount of moles that react with the sodium hydroxide must be known. This is achieved by using the method of back titration.
This research task and practical is performed with the aim of investigating the formation of esters through the reaction between different alcohols with carboxylic acids and discussing their usage as
...light of paracetmol’s physiological effects. The compound exhibits characteristics that mirror other analgesics and anti-pyretics but also displays unique properties that can be advantageous in certain treatment plans. Its anti-inflammatory activity is not as strong as other similar medications known as NSAIDS; fully refereed to as non-steroidal anti-inflammatory drugs. The main mechanism proposed for paracetamol involves the highly selective inhibition of an enzyme called cyclooxygenase; abbreviated COX. There are two isoenyzmes of cyclooxygenase are of similar molecular weight and structure but each take on different functions. They are labeled COX-1 and COX-2. COX-1 is present in most tissues and but functions more specifically on maintaining the lining of the stomach. It also plays other vital roles within the body such as platelet and kidney function.
·Aspirin (salicylic acid acetate) is an anti-inflammatory (decreases swelling and inflammation), anti-pyretic (fever reducing), and anti-platelet (decreases platelets in the body to thin blood). Many heart treatment patients take an aspirin a day to prevent blood clotting. However, if aspirin is taken in large quantities over long periods of time, it may cause gastric ulcers or other internal damage. The molecular formula of aspirin is C9H8O4. Some examples of Aspirin are Bayer, Ecotrin, and Aspergum.