The theoretically yield for the experiment is 85%, so the percent recovery was low. The nitrating mixture must be made in situ as required and kept cool throughout. Categories Tags, , , Post navigation. This experiment covered 4 techniques; they are distillation, refluxing, extraction, and esterification. Is the ester group of your starting material electron donating or withdrawing? Results: Theoretical Yield: Methyl Benzoate: 0. Continuously swirl the ester solution in the ice bath as you add the mixture of acids.
When dry, determine the weight and melting range of the solid. These techniques allow the chemist to derive functional groups and isolate unknown compounds that can verify and identify unknown compounds often obtained through academic and commercial laboratory research projects. The objective of this experiment is to synthesize methyl m-nitrobenzoate from methyl benzoate and will be purified by recrystallization with methanol. After that, vacuum filtration and recrystallization were methods used to obtain the final product with minimal impurities. Conclusions: In this experiment, I started by adding 560 µL of sulfuric acid to a 5mL conical vial that contained a conical spin vane. The Arenium later shifts a proton to the bisulfate ion, forming the methyl 3-nitrobenzoate.
The second test tube contained 3 mL of deionized water. Conclusions The percent recovery of methyl benzoate for the experiment was 62. Firstly, esterification and refluxing, the acid and alcohol are first warmed and mixed together with the sulphuric acid catalyst then attached it to a reflux condenser for a period of time. This should be carried out on an electric hot plate to avoid naked flames. This may prevent damage to the vessel and thermometer by keeping the two objects stationary and the thermometer away from the magnet. By the concept of resonance, we can label alternately electron-rich and electron-poor carbon atoms around the ring.
Pour the mixture, with stirring, over about 150 cc of crushed ice. Explain what was done in this experiment to drive the reaction toward ester formation. Sulfuric acid causes acid burns on the skin. Purification and analysis Methyl 3-nitrobenzoate is insoluble in water but soluble in hot ethanol. As we know sulphuric acid are extreamly corrosive and can cause severe burns while nitric acid is one of the strong oxidizing agent so we need to wear gloves while doing an experiment. For the melting point of re-crystallized product, it is recorded as 80 degrees Celsius, and the true melting point with 78 degrees Celsius.
Waste Disposal The aqueous and ethanol washings from above are combined in a 100 mL beaker. These were then placed into an ice bath. While separating the layers, it gauge when to close the stopcock perfectly, so that led to a loss of eventual product. Pour methyl benzoate into cool concentrated sulfuric acid and keep the temperature below 10oC. Wash the crude product with a little ice-cold water. This conical vial was then placed into an ice bath to cool for five minutes. Support your conclusion with resonance drawings.
Questions Record the following data. Allow the solution to cool. Be very careful in handling the concentrated sulfuric acid and nitric acid. The mass of product collected was 3. The pH is adjusted to lie between 5. For this reaction, the physical properties of interest are as follows: Methyl m-Nitrobenzoate can also be produced using other techniques.
The solution is continuously cooled at 0°C. This means the actual starting amount was slightly lower than measured. Therefore the reaction is regioselective for nitration at the 3-position. The isolated product will be purified by recrystallization, and purity will be determined from the melting point. Pour the solution into ice bath, filtrate the solution wash by methanol. Experimental yield and percent yield show calculations 5. Naturally, this element would seek a position of greater positive charge, namely an ortho position.
This is the mechanisms of for nitration of methyl benzoate: Nitration is an introduction of nitrogen dioxide into a chemical compound acid. Observed Yield of Product Weight of benzoic acid: 10. The solution was then mixed for an additional 10 minutes and separated by pouring onto 10 g of cracked ice. The melting point of our product is 75˚C - 78˚C and 76˚C - 78˚C. Procedure Bring a clean, dry 25 x 150 mm test tube to the storeroom manager and trade it in for a 6. While this reaction is a possible alternative, the rate of the reaction may be too slow to be practical due to the extremely strong deactivating nature of a nitronium group on the aromatic ring.
Both benzoic acid and methanol are relatively cheap to obtain from a commercial source as well as being easy to store with a relatively long shelf life. The ester group is the meta deactivator and the reaction takes place at the meta position because the ortho and para positions are destabilized by adjacent positives charges on the resonance structure. Therefore, bromine should seek to add to this position also, which we observe. Pour the mixture, with stirring, over about 150 cc of crushed ice. Interpretation of data and conclusion. Our percent difference is computed as 2.