Sulfuric acid was used as a catalyst to speed up the decomposition rate of salicylic acid. The percent yield is a way of measuring how successful a reaction has been. If you have difficulty, look at the banana oil experiment. Application of sample - capillary open on both ends is used to spot the solution of each sample 2. Be sure the water is near freezing to minimize loss of product. Crystallization should begin once the solution reaches room temperature. Thus, cold water and ethanol was used to rinse the solution and the solvents in which salicylic acid and aspirin needed to be dissolved was placed in the warm bath to increase temperature.
With specialized tools, it is probable that efficiencies of 90% or more are possible in large-scale, commercial applications of the synthesis of Aspirin. Leave the 125 mL Erlenmeyer flask that contains the mixture in its ice bath and allow it to cool for an extra 5 minutes. The percent yield of crude aspirin product was 91. Since aspirin has a hydrophobic aromatic ring, it did not dissolve in water. The beaker was placed on the hot plate. Thus, they are slightly soluble in water when being highly soluble in ether or other organic compounds.
Reflux involves the condensation of vapours and the return of the condensate to the system from which it originated. Calculate amount of acetic anhydride needed amount of salicylic acid times 3 2. Add 10 mL of ethanol. This is the second part of the purification process. Firstly, the amount of materials could be increased. Each sample was transferred into a clean and dry 125mL Erlenmeyer flask before each titration.
Data Aspirin was first synthesized by a German chemist named Felix Hoffman in 1897. One possibility is the salicylic acid. Aspirin belongs to non-opioid analgesics. When liquid is placed in a narrow vertical glass tube, the forces of adhesion and cohesion will cause to form a curve in the tube. There are a few sources of error in this particular experiment. Turn the capillary tube back to the upright position.
Knew because the compound did not dissolve in water. For the sake of time and efficiency, sulfuric acid was added as a catalyst to speed up the reaction. Furthermore, in the process of cooling, the solution containing the precipitate was kept in a fridge, where a mixture of lead nitrate and potassium iodide also was kept. Lab Report Introduction This lab has the following two concepts: synthesis of acetylsalicylic acid and analysis of acetylsalicylic acid. In 1763, the Reverend Edward Stone introduced these extracts and teas to the Europeans and in the early 1800's the active ingredient in willow bark and in the flowers of the meadow sweet plant which had similar therapeutic characteristics was isolated and identified as salicylic acid from salix, the Latin name for the willow tree. Sulfuric acid serves as the acid catalyst since its conjugate base is a strong deprotonating group that is necessary in order for this reaction to be reversible.
Over history, many compounds obtained from nature have been used to cure ills or to produce an effect in humans. After adding the acetic acid anhydride and the sulfuric acid into the flask, the. Ibuprofen is sold under the brand name Advil and Acetaminophen is sold under the brand name Tylenol. A Melt-Temp apparatus is used in this experiment as well in order to find the melting point of the synthesized substance. Since lead ions would not react with acid, the total mass of compounds that took part in the titration reaction would significantly decrease resulting in a more reasonable average molecular mass of the impurity.
Acetylsalicylic acid, also known as aspirin, is one of the most widely used medications to reduce fever and is also used as a pain killer. Using the upright balances, weigh out 2. Before the crude aspirin was recrystallised it may have contained various impurities that were not all eradicated by the precipitation process, these could include: contaminations in the air and C2H4O2 a product of the original reaction , along with contaminations in the distilled water used, although this is better than using tap water. In this case, an acetyl group was added to salicylic acid, a naturally occurring compound with significant pharmaceutical value. This will create positive charge on both the protonated oxygen. Also, the melting point range will seem broader than it really is.
Plug caps for 13x100 mm tubes —Ms. Then, its active ingredient, salicylic acid was first discovered by an English pastor, Reverend Edward Stone, when he administered powdered willow bark on patient and observed its effect on them. In the process of aspirin synthesis mechanism, the protons of the acid reacts with the acetic anhydrate to bond with both oxygen with double bond and in between the acetate groups. During this semester, you will have an opportunity to isolate some pharmacologically active natural products and to synthesize other active compounds from suitable starting materials. Test this crude product for the presence of unreacted salicylic acid using the ferric chloride test. These mechanisms for this experiment can be seen in Scheme 1.
Also, set up an ice bath for the mixture in the Erlenmeyer flask as well as a second ice bath for the 100 mL beaker while waiting for the mixture in the Erlenmeyer flask to heat. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. Air dry the crystals and transfer them to a watch glass to dry. Calculate the % recovery of recrystallized material from crude material. Analgesics are compounds used to reduce pain, antipyretics are compounds used to reduce fever.