Introduction SN2 stands for substitution, nucleophilic, bimolecular and occurs in one step where the nucleophile and electrophile react: the nucleophile attacks the electrophile 180° from the leaving group.3 The leaving group is nothing more than a group that leaves the electrophile attacked by the nucleophile. In this experiment the nucleophile is bromide, the electrophile is 1-butanol, and the leaving group is hydroxide. However, bromide must first be obtained from hydrobromic acid which gets bromide from a reaction between sodium bromide and sulfuric acid. The hydrogen and bromide in hydrobromic acid reacts with the oxygen in 1-butanol and the carbon attached to oxygen respectively to form 1-bromobutane. The overall reaction of this procedure …show more content…
Mixture was cooled in ice bath for ten minutes and 11.5mL of concentrated sulfuric acid was carefully added while flask was swirled in bath. Flask was put into electric flask heater clamped securely to a condenser. Mixture was heated to boiling point for reflux condensation. Reflux continued for 45 minutes without allowing reactants to evaporate so that alkyl bromide and salt layers could form; afterwards, flask was removed from heat and condenser cooled and drained. Flask is removed from condenser and attached to a still head while condenser is set up for simple distillation. Mixture was heated to 115°C to distill organic layer into Erlenmeyer flask. Distillate was then poured into separatory funnel with 10mL of water. Funnel was shaken, vented every few shakes, and allowed to set for two minutes. Bottom layer is 1-bromobutane which is drained into clean Erlenmeyer flask. 1-bromobutane is dried with 1g of anhydrous calcium chloride until liquid became …show more content…
Mass of sodium bromide and volume of 1-butanol were used to calculate theoretical yield of 1-bromobutane. Simple distillation was performed on 1-bromobutane to eliminate impurities in the product. Distillation was performed at 115°C to allow all the 1-bromobutane to distill. Fractional distillation was performed afterwards at a boiling range of 99-103°C to further remove impurities from product. Products obtained were used to calculate percent yield of 1-bromobutane. Lastly, product was GC traced to obtain the percentage of product and starting material within final product. Observations: Mixture turned yellow as sulfuric acid was added. During reflux condensation, sodium bromide dissolved and brown layer formed on top of solution as it boiled. Brown layer was alkyl bromide while clear, bottom layer was inorganic salts. After simple distillation, product was clear and colorless. 1-bromobutane remained clear and colorless after fractional distillation. GC trace showed that there was a small amount of 1-butanol in final