Possibly the largest source of product loss could come from the reaction not occurring fully. Section I — Procedure: summarize the procedure using a flow chart format. This addition of cold water is very important in purification and isolation of the crystals from the liquid since aspirin is insoluble in cold water. While the Aspirin is crystallizing, chill 60 mL of distilled water in a second ice bath. Rinse the residue on the filter paper with 2 mL of ice-cold deionized water. The test used in this part was Iodine test, which is a test for the presence of starch since iodine can form a black complex with starch.
All chemicals were disposed of properly. Changing a variable will not affect these constants. Its rate was a littler lower than Sulfuric Acid, but much higher than the base catalysts. Remove a pea-size amount of the crystals from the Büchner funnel and set aside to determine the melting point and infrared spectrum of this crude sample. Regarding the process of recrystallization, it appears that agitation, shock, and low temperature can all help the recrystallization proceed at a faster rate. Add 10 mL of cold water and 10 mL of ice to the Erlenmeyer flask and stir. This experiment also taught the importance of diligence and following directions carefully.
It is possible to repeat this process in order to end up with the desired amount of substance in the end. Experimental Section Mix salicylic acid, 85% phosphoric acid, acetic anhydride, and a boiling stone in a conical vial. By replacing the arbitrary large amount of substance that was on the balance at first, it is then possible to view the total amount of substance removed from the large arbitrary amount and is, consequentially, in the desired receptacle. If the mixture becomes cloudy or crystals start to appear, reheat the contents again and allow the beaker to cool down again. After the 15 minutes are done, use the filter crucible, water aspirator, and plastic filter flask to isolate the Aspirin crystals from the liquid. It also will attack metals, forming sulphates, and givin … g off hydrogen, an explosive gas. Salicylic acid is great for treating pains; however it is highly acidic and damaging of mucous membranes.
The reactivity of an element depends on its ability to gain or loose electrons which are used for bonding. Another laboratory procedure used in this procedure is reading and recording liquid volumes. Salicylic acid was neutralized with sodium to produce sodium salicylate, which was better-tasting but still irritated the stomach. It is a very corrosive acid and is a 1 or so on the pH scale which is very acidic. Put each compound in a test tube, added about 1 mL of ethanol, and added 3 drops of 0. Interpretation of results - comparison of retention factors -Has a smooth side and a rough side.
The chemical name for aspirin is acetylsalicylic acid. The acetic acid and phosphoric acid can be removed in the washing of the aspirin in cold water since they are soluble. Stir to dissolve it completely, and then add 5 mL of warm 70°C deionized water. For the experiment, the starting materials are salicylic acid, acetic anhydride, and phosphoric acid. Aspirin is synthesized by using acetic anhydride or acetyl chloride to acetylate salicylic acid.
Introduction: Traditionally, many pains were treated with salicylic acid. Do reaction using 90% of that salicylic acid. Some catalysts might work too slowly and might not have fully facilitated the reaction during the allotted time in the test tube. The test amplifies the number of copies of the genetic material in order… Gamido, Mitchiko Mariel M. Then, after resetting the balance, take the large arbitrary amount of substance and transfer some of the substance to the desired beaker or other receptacle. The identity of the unknown liquid was Hexane, with a measured boiling point of 70… 1491 Words 6 Pages 5 February 2015 Experiment 1: Utilizing Melting Point and Boiling Point to Determine Unknowns Introduction: One of the first topics learned in most chemistry class is the relation between physical and chemical change.
Reference Data, Experimental Volumes, Yields, and Melting Points Melting Point of Salicylic Acid 158° C Melting Point of Acetylsalicylic Acid 138° C - 140° C Initial Mass of Salicylic Acid 0. A vacuum filtration system was setup, and the filter paper was placed into the set up. How did this affect the end product? However, the above is the most efficient and common way of synthesizing Aspirin. To measure an amount of a liquid, the liquid to be measured is poured into the graduated cylinder. Be careful not to heat the water bath above 85 ˚C. The actual yield of Acetylsalicylic Acid was 3.
Using the upright balances, weigh out 2. While many variables can change in the experiment, there are many variables that are independent controllable as well. Looking at results from the Melt-Temp apparatus, it appears that more impure samples have longer, less precise melting points. The dependent variables in the experiment are the variables that are not completely controllable: percent yield, speed of crystallization, co-crystallization of Salicylic acid or Acetic Acid, or anything else not changeable by the person running the experiment. Knew because the compound did not dissolve in water. If the meniscus curves up, then the correct reading will be at the bottom of the meniscus.
At higher temperatures warm water , molecules have more kinetic energy and collide with each other more often to interact with water molecules, increasing the solubility of the aspirin. Trials 1-4 show the results of the calibration solution which were used to calculate the phosphoric acid concentrations in the Pepsi-Cola. The purity of the sample will be qualitatively determined with melting point analysis. Also, the melting point range will seem broader than it really is. 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.
Washing the aspirin removed most of the unreacted salicylic acid and acetic anhydride to yield a purer product. From that structure we can begin to understand why and how chemical reactions occur. The reason that a bottle of old Aspirin might smell like acetic acid is because the acetylsalicylic acid undergoes hydrolysis leaving Salicylic Acid and Acetic Acid. Conversely, if the meniscus curves down and forms a sort of dome, the proper measurement is at the top of the meniscus. There are many instruments that can be used to measure liquid amounts that differ in measuring capacity and accuracy, but the one used in this experiment is the graduated cylinder. Record the mass to the nearest 0. Stirring constantly, the thermometer was observed for a 4°C temperature change.