Discussion and Conclusion: Preparation of 1-Bromobutane
The purpose of this experiment was to demonstrate the conversion of a primary alcohol, 1-butanol, to a primary bromoalkane, 1-bromobutane, a SN2 reaction. The conversion of 1-butanol to 1-bromobutane relies on sulfuric acid which plays two important roles. First, it protonates the alcohol of 1-butanol to form an oxonium ion which is a good leaving group. Secondly, it produces the hydrobromic acid, the nucleophile, which attacks 1-butanol causing the oxonium ion to leave and forming 1-bromobutane. However, using sulfuric acid in this experiment has several downsides. First, it poses a huge safety hazard as it can cause severe burns. Secondly, it reacts exothermically, which was solved by using an ice water bath. Lastly, it produces several side products including dialkyl ether and alkyl hydrogen sulfate. After mixing all the reagents, they mixture was placed under a gentle heat reflux in a simple distillation. This allowed the reaction to occur, but also removed any excess sulfuric acid and hydrobromic acid. This should have left water, 1-bromobutane, and any side products in the remaining distillate. The 1-bromobutane was isolated by stirring the distillate in 250 mL of distilled water because the side products as well as the water are less dense than the 1-bromobutane. This caused the 1-bromobutane to sink to the bottom and thus allowing it to be separated. The total amount of 1-bromobutane formed was 2.065 grams. In order to confirm that the reaction occurred correctly and that 1-bromobutane was formed, infrared spectroscopy as well as halide tests were performed on the product.
Infrared spectroscopy works on the basis that different covalent bonds of molecules can stretch and bend. These bonds can undergo vibrations which require energy that corresponds directly with the energy absorbed from infrared radiation. Consequently, each bond will absorb different spectrums of infrared radiation. The...
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