When this happens your mass decreases and inaccurate results will show. Set up a 150 mL beaker with water to warm up on a hot plate medium heat 2. Empty the solution from the filter flask and draw air over the crystals. The mechanism of this reaction can be understood by examining the Lewis structures of each reagent. Experiment starts off by taking salicylic acid and mixing it with the acetic anhydride.
Figure 2 shows the process of filtration. Obtain mass of dry salicylic acid. The end product is pure dry aspirin. Clean the reaction beaker to remove Acetic Acid from it, and then return the Aspirin crystals from the filter crucible to beaker. Magnesium Aluminum Zinc Iron Copper Prediction: Aluminum. Development of sample - this is when the separation actually occurs 3.
Paper covers all holes, but does not come up the sides -Pour crystals in solvent on top of the filter paper -Rubber stopper, clamp, connected to vacuum trap. Though the experiment proved the hypothesis to stay true, several improvements could have been made to the procedure. In 1897, Felix Hoffmann discovered that there was indeed a way to make this drug less irritating to the throat and stomach: by reacting Salicylic acid with Acetic Anhydride, it would be possible to acetylate the Salicylic acid to remove one of these proton-donating groups and thus make it less irritating to the body. This will give us a decimal, in which we can calculate the percentage. 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. Using a clean, dry 150 mL beaker, dissolve the aspirin in about 1mL of 95% ethyl alcohol, and warm the mixture slightly by placing it in the hot water bath.
All of the physical characteristics of the different chemicals in Figure 3 are constants, as well. Stir to dissolve it completely, and then add 5 mL of warm 70°C deionized water. The actual mass obtained is 121. One of the more obvious things seen is the inefficiency of small-scale synthesis reactions. Another important thing that can be gleaned from this experiment is the use of a catalyst to speed up a reaction. The end product is aspirin, but in the crude form.
A Melt-Temp apparatus is used in this experiment as well in order to find the melting point of the synthesized substance. The purity of the sample will be qualitatively determined with melting point analysis. Recrystalization is the treatment process of taking the crude aspirin which is contaminated with the impure sulfuric and salicylic acid and separating them from the aspirin. In this experiment, you will prepare aspirin from salicylic acid and acetic anhydride using sulfuric acid as a catalyst. The percent purity of a sample describes what proportion of that sample, by mass, is composed of a specific compound or element.
Simply take the mass of each reactant and divide it by the given molecular weight. Those two chemicals are mixed together along with to form a crude solid. The equipment that was used was very much basic except the odd few. Record the mass to the nearest 0. Scraping solids of filter paper. This can be observed in both the use of Phosphoric Acid in the synthesis part of the experiment and the use of scratching the side of the beaker to induce crystallization.
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. It may be possible to simply leave the product in the crucible and rinse it directly after squeezing the excess liquid out, thus reducing the amount of lost product due to transfers. Since the salicylic acid is being completely used up in the reaction, this is the limiting reagent. 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. Observed that paste turned white 6.
In this reaction it is the salicylic acid. C1 - Calculate the moles of each reagent and determine the limiting reagent for this reaction. Clamp the stoppered Erlenmeyer flask to a ring stand to hold it in the 70-80˚ C water bath. With the yield percentage and the purity of the product, one can get an accurate picture of the efficiency of this process. Though there was too much room for error the yield percentage will almost never be a hundred percent. Conducted aqueous FeCl3 test on both the salicylic acid control and the aspirin. Magnesium 10 Aluminum 15 Zinc 30 Iron.
How to calculate the percent yield? The theoretical yield is the maximum amount of product that can be obtained in a chemical reaction. The process of vacuum filtration uses a filter crucible, an aspirator, and a vacuum hose in order to separate a liquid from a solid. Knew because the compound did not dissolve in water. After doing this, heat the beaker gently until it begins to boil, at which point remove it and allow it to sit for three minutes. 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.