Majority of the time, to prepare alkyl halides is via the nucleophilic substitution reactions of alcohols. SN2 reaction is the type of reaction used in this lab experiment. Our objective was to see how a primary alkyl halide reacted with an alcohol. We did a conversion of n-butanol to 1-bromobutane. Br- ions is the nucleophile for this reaction which is generated from an aqueous solution of NaBr. The catalyst that converted the OH functional group of butanol to a better leaving group (H2O) was the Sulfuric Acid. [pic]
C4H9OH + NaBr -------> C4H9Br + NaOH
20mL (butanol) x 0.810g (butanol) x 1mole (butanol) x 1mole(bromobutane) x 137.03g(bromobutane) = 29.95 g of 1bromobutane 1.00 mL(butanol) 74.12g(butanol) 1mole(butanol)1mole (bromobutane)
27g (NaBr) x 1mole (NaBr) x 1mole (bromobutane) x 137.03g(bromobutane) = 35.95 g of 1bromobutane 102.91g (NaBr) 1 mole (NaBr) 1mole (bromobutane)
% Yield = 4.74g / 29.95 g = 15.8%
Volume ( 3.8mL
Mass ( 4.74g
4.74 / 3.8 = 1.246 g/mL
After proceed with our four major operations that were refluxing, simple distillation, separation and drying, we could do our corresponding calculations. Refluxing was used to keep a reaction at a constant temperature. Simple distillation was used to help remove and purify a particular substance in that case was 1-bromobutane, from other components in the reaction flask. Separation was carried out because there was a high probability of other components in the distillate. And finally we used CaCl2 as a very good drying agent for a variety of solvents. So for instance, 1-butanol is the limiting reagent, theoretically 29.95g of 1-bromobutane. Our percent yield was 15.8% as showed in the calculations. Our volume was 1.247 g/mL. And as finally our boliling point was 99C.
• Show the mechanism for the reaction perfomed in the...