That means that sooner or later, the extra ~32 grams of acetanilide should precipitate out of solution also known as crashing out. Principally, acetanilide gives Ortho and Para mono nitroacetanilides. The sample was weighed to be 3. Whilst preparing the mixture of Nitric acid and sulphuric acid, I misjudged the reading on the measuring cylinder once again due to time constraints and consideration toward my fellow peers. The para form was separated from the ortho form based on solubility properties using recrystallization techniques. Therefore Ortho and Para positions are more resonance stabilized than the Meta.
Using a filter flask and a Hirsch funnel the product was isolated by suction filtration. Vapor Pressure: The vapor pressure for this compound is 2 Pa at 20 °C. It is predicted that substitution order from most to least reactive should be aniline, phenol, anisole, and acetamide. Calculate the percent yield of nitrobenzene. The nitration is performed in an ice bath to keep it stable during the addition of each compound. Mixture of concentrated sulphuric and nitric acid will produce a nitronium ion, which will attack ortho-, meta- and para- positions at Toluene. Regioselective Nitration of Acetanilide Essay Sample Introduction: Table of reagents Compound Mol.
In order to prevent di-nitration of the acetanilide, the mixture of the two acids had to be added in small portions to the acetanilide solution, so that the concentration of the nitrating agent is kept at minimum. Reflux the mixture for 20-30 min. The substituents being tested are aniline, anisole, acetamide acetanilide , and phenol. Nitration of Methyl Benzoate Date of Completion: February 29, 2012 Date Report Submitted: March 14, 2012 Objective of Experiment: The purpose of this experiment is was to synthesize methyl 3-nitro benzoate from methyl benzoate through an electrophilic aromatic substitution reaction. Once the initial quantity of methyl benzoate is known, the molar ratio of reactants to products can be used to determine the theoretical yield.
Otherwise, more of your product will stay dissolved in the solvent when you cool it back down, and you will collect less product. Scoop your solid onto a pre-weighed drying dish. At this point the solution is said to be saturated. Para isomers are more favoured over ortho isomers due to steric interaction in ortho isomers. Q: A student performed this experiment using 0. By filtering the liquid- the black pepper will get stuck in the filter paper, and you can continue to recrystallize the liquid solution as normal. A purified product will show a melting point close to that of methyl 3-benzoate, 78 ºC.
I placed 4 small ice cubes in a 125 mL Erlenmeyer flask along with ~20 mL of cold water. This determines the starting number of moles of methyl benzoate. Once dissolved, I removed the flask from the heat and allowed it to cool to room temperature undisturbed until crystals form. So how do you remove it? Also in this report will be an outline. After you added and weighed the aniline, add 6-7 drops of acetic anhydride. Reaction: Reaction mechanism: Safety Notes: Sulfuric acid and nitric acid can cause very serious burns, and they react violently with water and other chemicals.
Over a period of 10 minutes, add 1. The purpose of this experiment was to nitrate naphthalene with nitronium ion, which is formed at low concentration from a reaction of nitric acid and sulfuric acid. This was filtered through a Buchner funnel, using plenty of water. Non polar compounds are soluble in non-polar solvents such as hexanes and diethyl ether. But the student only collected 0. In a 50 mL Erlenmeyer flask, I combined concentrated nitric acid 0. The flask was placed on the stir plate for about 10 minutes.
Fire Fighting Measures It can be combustible at very high temperatures. Electrophilic Aromatic Substitution Objective The objective of this experiment was to illustrate electrophilic aromatic substitution by synthesizing p-nitroanilide as well as ortho from acetanilide by nitration. The addition of nitric acid would be exothermic so the mixture would have got too hot and overpass the maximum temperature range suitable for the nitration this is why less was used and why it was added slowly. Aniline and acetanilide contain amine groups, which are electron-donating. The nitro naphthalene is a suspected carcinogen; avoid contact.
Reaction scheme of the electrophilic aromatic substitution of methyl benzoate Figure 3. In the second step p-nitroaniline is prepared from p-nitro acetanilide due to hydrolysis of acetate ion from acetamido functional group in presence of concentrated sulphuric acid. The nitronium ion is then reacted with toluene to create a combination of ortho, meta, and para-nitrotoluene see mechanism below. However, meta attack on a deactivated ring is favored because the meta-directing, electron-withdrawing groups avoid the positive charge on the carbon that carries the substituent. Nitric acid produces toxic nitrogen dioxide fumes during the reaction. When the solvent cools back down again, the solid will precipitate out of the solution and leave the impurities behind, still dissolved in the solvent. Empty containers pose a risk of causing fire hazards so they should be treated under a fume hood in order to evaporate any residue in them.
First is the substitution by bromination. The mixture was also washed with 2. Nitration of Acetanilide A nitro group substitutes a hydrogen atom in the aromatic ring of Acetanilide in this electrophilic aromatic substitution reaction. For the melting point of re-crystallized product, it is recorded as 80 degrees Celsius, and the true melting point with 78 degrees Celsius. In conclusion, our product is considered pure because our melting point range did not exceed 3. Ammonium hydroxide was then titrated slowly into the conical flask and the conical flask.