1-Bromobutane Lab Report

As relayed in Table 1, the results concluded that the only molecules to react and form a precipitate were 1-chlorobutane and 1-bromobutane. 1-bromobutane formed a precipitate first, after two minutes and eight seconds. 1-cholorobutane did not for a precipitate until after heat was applied after seven minutes and fifty-one seconds. 2-cholorbutane, 2-bromobutane, and tert-butyl-chloride did not react at all during the course of the experiment. 1-bromobutane was expected to react first, followed by 1-chlorbutane. As shown by Figure 3 and Figure 4, the structure of the molecule indicates the leaving groups to be primary. The leaving groups in this case are chlorine and bromine. This is important because the reaction was a bimolecular nucleophilic

The nucleophile in this particular SN2 reaction was iodine and, as stated before, the leaving groups for 1-bromobutane and 1-chlorobutane are bromine and chlorine respectively. Bromine is a better leaving group than chlorine however, so the fact that 1-bromobutane reacted before 1-chlorobutane corresponds directly with what would be expected. As stated before, primary is more reactive than secondary and even more reactive that tertiary. This explains why no reaction/change was seen for 2-chlorobutane, 2-bromobutane, and tert-butyl-chloride. 2-bromobutane would have been expected to react next, due to bromine being a better leaving group than chlorine, then 2-chlorobutane. Tert-butyl-chloride would be expected to never react in a SN2 reaction, as it is so unreactive under these conditions. For each of the molecules used in this experiment (except tert-butyl-chloride), the nucleophile, iodine, would attack the electrophilic carbon bonded to the leaving group, chloride or bromide. That leaving group would then take the

To find the reaction times of 2-chlorobutane and 2-bromobutane, the reaction time could have been extended. As these reactions might take days to react, they could have been left to analyze at a later date. The only problem with extending reaction time, is the increased error and decreased precision, as the reaction time might not be able to be measured in minutes. Unless someone could monitor the reaction at all times and accurately record the time the precipitate was noticed. Another improvement could be to increase the concentration of the reactant. If more reactant is added this may speed up the reaction time for 2-chlorobutane and 2-bromobutane. One other improvement that could be made is by using a different solute instead of acetone. DMSO, DMF, or CH_3CN could all be used. Although these chemicals are more dangerous than acetone, they have a higher boiling point and so if the reaction could be heated more, this would speed up the reaction and hopefully yield a reaction from 2-chlorobutane and