Nitration of acetanilide free essay sample

The experimental procedure was conducted as per instructions from the chemistry 220 manual. We were told to add 5grams of Acetanilide but due to time constraints I had added 5. 05grams. 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. As indicated, we were instructed to add the mixture drop wise; I had allowed the tap to run due to a confusion of the tap mechanism. The mixture therefore went up to 20 degrees and dropped gradually back to 11 degrees . After adding a little over 45mL of methanol, in order to start the process of recrystallization, my product was still cloudy. I feel I therefore may have added too much to re-dissolve the product. It took time for my product to break down over the steam and dissolve, yet eventually, suggested by the demonstrator I left it to become fully crystalized once again therefore becoming a ice cold slurry. We will write a custom essay sample on Nitration of acetanilide or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Thereafter filtration took place. Reaction Mechanism: Reference:www. kshitj-school. com en. wikipedia. org Melting point of substance prepared: Para-nitroacetanilide= 214-217 degrees Celsius(http://content. hccfl. edu/faculty/bertrubini/2211%20-%20Electrophilic%20Aromatic%20Substitution. pdf) Melting point of substance prepared: Expected yield: Calculation of yield Limiting agent –acetanilide Moles for limiting agent=5. 05g/135. 16g/mol=0. 0374mol Moles of product=1/1*0. 0374=0. 0374mol Mass product expected=0. 0374*180. 16g/1mol=6. 74g Short discussion: Critical point in this experiment is, due to aromatic nitration of Acetanilide being an exothermic reaction, the temperature must constantly be monitored and there must be slow additions of all reagents. Also every acid must be removed due to hydrogen ions, catalysing the hydrolysis of the amide to p-nitroaliline. Nitronium ion is formed by mixing the concentrated sulphuric acid and nitric acid. An improvement that could be made to the experiment is that the steam baths should have been singular units so we could monitor our substances more thoroughly.