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16 Nov 2019
When an alcohol (substrate) is placed in an excess equimolar amounts of chloride ions and bromide ions in acid media the corresponding alkyl halides are obtained. The ratio of the alkyl halides depends orn several factors: the nature of the substrate, the reaction conditions, the solvent and the mechanism of the reaction When tert-butanol is placed in the presence of excess equimolar amounts of chloride and bromide ions in aqueous acid experimental data indicates 45% tert-butyl chloride and 55% tert-butyl bromide is obtained. This outcome can be explained by the fact that the rate determining step of the reaction does not involve the nucleophile, and once the carbocation is formed it is equally available to each nucleophile On the other hand, when n-butanol is placed in the presence of excess equimolar amounts of chloride and bromide ions in aqueous acid experimental data indicates 16% of n-butyl chloride and 84% of n- butyl bromide is obtained. The difference in the outcome can be explained by the fact that the rate determining step of this reaction requires the presence of the nucleophile, and in aqueous media the small size chloride ion gets "trapped" in the aqueous solvent cage and the bromide ion therefore gets a better chance to attack the substrate. This point can be demonstrated by changing the solvent. When n-butanol is placed in the presence of excess equimolar amounts of chloride ions and bromide ions in acid dimethyl sulfoxide the experimental data provides an 84% n-butyl chloride and 16% n-butyl bromide as the outcome. or all three reactions (hint: account for the mole ratiosl). 2. Draw complete mechanisms for all three reactions 3. Calculate the theoretical yield for chlorides and bromides if each reation was started with 2.5 mL of the corresponding alcohol, using an aqueous acid media. Place your results in a data table format. Sample Theoretical g of chloride Theoretical g of bromide tert n- 4. Calculate the expected percentage yield of each halide if you obtained a total of 0.025 moles of tert- nd 0.022 moles of n-butyl halides, and your % composition corresponds to the values butyl halides a of refractive index indicated and using an aqueous acid media. (hint:complete the data table) Sample # | Refractive | Temp. | % a (RI) | %Br (RI) | Mass ci | Mass Br % Yield Index of mixture ! !Tert-butyl| 1.4042 In-butyl 11.43 11 | 25.7â 126.1â 5. What would be the expected refractive index for the reaction of n-butanol with an excess of equimolar amounts of chloride and bromide ions if the reaction took place in dimethyl sulfoxide? No need to do calculations for the third reaction, just the first two.
When an alcohol (substrate) is placed in an excess equimolar amounts of chloride ions and bromide ions in acid media the corresponding alkyl halides are obtained. The ratio of the alkyl halides depends orn several factors: the nature of the substrate, the reaction conditions, the solvent and the mechanism of the reaction When tert-butanol is placed in the presence of excess equimolar amounts of chloride and bromide ions in aqueous acid experimental data indicates 45% tert-butyl chloride and 55% tert-butyl bromide is obtained. This outcome can be explained by the fact that the rate determining step of the reaction does not involve the nucleophile, and once the carbocation is formed it is equally available to each nucleophile On the other hand, when n-butanol is placed in the presence of excess equimolar amounts of chloride and bromide ions in aqueous acid experimental data indicates 16% of n-butyl chloride and 84% of n- butyl bromide is obtained. The difference in the outcome can be explained by the fact that the rate determining step of this reaction requires the presence of the nucleophile, and in aqueous media the small size chloride ion gets "trapped" in the aqueous solvent cage and the bromide ion therefore gets a better chance to attack the substrate. This point can be demonstrated by changing the solvent. When n-butanol is placed in the presence of excess equimolar amounts of chloride ions and bromide ions in acid dimethyl sulfoxide the experimental data provides an 84% n-butyl chloride and 16% n-butyl bromide as the outcome. or all three reactions (hint: account for the mole ratiosl). 2. Draw complete mechanisms for all three reactions 3. Calculate the theoretical yield for chlorides and bromides if each reation was started with 2.5 mL of the corresponding alcohol, using an aqueous acid media. Place your results in a data table format. Sample Theoretical g of chloride Theoretical g of bromide tert n- 4. Calculate the expected percentage yield of each halide if you obtained a total of 0.025 moles of tert- nd 0.022 moles of n-butyl halides, and your % composition corresponds to the values butyl halides a of refractive index indicated and using an aqueous acid media. (hint:complete the data table) Sample # | Refractive | Temp. | % a (RI) | %Br (RI) | Mass ci | Mass Br % Yield Index of mixture ! !Tert-butyl| 1.4042 In-butyl 11.43 11 | 25.7â 126.1â 5. What would be the expected refractive index for the reaction of n-butanol with an excess of equimolar amounts of chloride and bromide ions if the reaction took place in dimethyl sulfoxide? No need to do calculations for the third reaction, just the first two.
Reid WolffLv2
12 Jun 2019