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Purpose:The intent of the experiment was to execute a synthesis of an alkyl halide by a nucleophilic permutation reaction. The alkyl halide. along with the get downing intoxicant. was determined through NMR spectrometry. gas chromatography. and IR spectrometry.
Experimental Procedure:In a 100 milliliter unit of ammunition underside flask. incorporating a Teflon splash saloon. 17. 123 gms of Na bromide. 17 milliliter of distilled H2O. and 8. 6 milliliter of unknown intoxicant were combined. Through the top of the capacitor. 14 milliliter of concentrated sulphuric acid was added bead wise over a period of 10 proceedingss. The add-on of the acid created a alteration in colour of the solution to a countrified orange colour. The mixture was refluxed for 30 proceedingss and the solution changed to a faded yellow-orange colour. Once reflux was complete. a simple distillment was set up. with the 25 milliliter aggregation graduated cylinder placed in an ice bath. The mixture was distilled and combined with the goon partners’ distilled mixture. The distillation was placed in a separatory funnel with 10 milliliter of distilled H2O. Once separated. the distillation was added to the funnel once more with 9 M sulphuric acid.
The organic bed was still in the funnel after separation. as distilled H2O was added to the solution and so 10 milliliter of a concentrated solution of Na hydrogen carbonate. The organic solution was dried with anhydrous Na sulphate for a hebdomad. The liquid merchandise was transferred to a 25 milliliter unit of ammunition underside flask equipped with a stir saloon and a simple distillment was set up. The solution was distilled and the denseness of the bromide was calculated at 1. 222 grams/mL with a boiling scope of 87-92?C. The theoretical output was calculated at 12. 847 gms and the per centum output was 72. 3 per centum. Next was the word picture and appraisal of the pureness of the alkyl bromide utilizing IR spectrometry. NMR spectrometry. and gas chromatography. Mentions: Mohrig. J. R. ; Morrill. T. C. ; Hammond. C. N. ; and Neckers. D. C. ; Experimental Organic Chemistry ; W. H. Freeman and Company: New York. NY. 1997 ; pp. 76-81.
Gilbert. J. C. ; and Martin S. F. Experimental Organic Chemistry. 2nd Edition ; Saunders College Publishing. Harcourt Brace College Publishers. 1998 ; pp. 383-385.
Consequences:Calculation of Theoretical Output:2-Butanol intoxicant: 8. 6 mL * 0. 808 g/mL = 6. 9488 gms6. 9488 g/74. 12 gms of 2-Butanol = 0. 0938 moles 2-Butanol17. 123 gms of NaBr / 102. 9 g/mol of NaBr = 0. 166 moles of NaBrAlcohol is the confining reagent.1 moles of intoxicant / 1 mole of 2-bromobutane = 0. 0938 moles 2-bromobutane0. 0938 moles 2-bromobutane * 137. 03 grams/moles = 12. 847 gms of 2-bromobutaneand theoretical output.
Calculation of Percent Output:9. 287 gms really obtained / 12. 847 gms theoretical output = 0. 72290. 7229 * 100 = 72. 3 % outputDensity of Alkyl Halide:Grams of distillation in calibrated cylinder/ volume of distillation in milliliter = 9. 287 gms / 7. 60 mL = 1. 222 g/mL of alkyl halide
Decision:The experiment performed was able to successfully place a starting intoxicant and alkyl halide utilizing reflux. distillment. lavation. and separatory funnel. Due to trials. such as gas chromatography. IR spectrometry. boiling point. and NMR spectrometry. being conducted. consequences for the experiment showed 2-bromobutane as the identified alkyl halide. IR Spectroscopy- the IR spectrometry trial was run in order to compare the functional groups of the get downing intoxicant along with the alkyl halide synthesized. The get downing intoxicant had the below functional groups appear on the IR spectrometer.
O-H – Alcohol| 3400. broad|C-H- Alkenes| 2900. strong and sharp|C-H – T butyl group| 1450. crisp. medium|C-O- Acids| 1000. crisp. medium|
In comparing to the functional groups of the get downing intoxicant. which showed grounds of a t-butyl group. the functional groups of the alkyl halide were examined. C-H – Alkenes| 2900. strong and sharp|
C-H – Alkyl Halides| 1200. crisp and medium|C=O- Carbonyl| 1700. crisp and low|
Both the intoxicant and the alkyl halide contained grounds of olefines. in about the exact same signifier. The intoxicant had H bonds that were non represented in the alkyl halide merchandise. The intoxicant and the alkyl halide contained assorted carbon-hydrogen bonds but differed in the functional group represented. The IR spectrums of the two merchandises were similar in bonds but differed in arrangement. reasoning that one was an intoxicant and the other was a bromide that formed. 1 H NMR Spectroscopy- the NMR spectrometry was used to find the chemical displacements. dividing forms. and the integrating ( figure of H atoms ) for the get downing intoxicant every bit good as the alkyl halide. The NMR tabular array for the starting intoxicant was analyzed foremost.
Chemical Shift| 3. 75 displacement1. 5 displacement1. 3 displacement0. 8 shift|Dividing Pattern| 3. 75 proton- four split1. 5 proton- three to singlet1. 3 proton- doublet0. 8 proton- triplet|Integration| 10 Hydrogen|
The NMR for the alkyl halide was analyzed below.Chemical Shifts| 1. 0 displacement of 2nd Carbon4. 1 displacement on the proton C to bromine1. 6 and 1. 8 displacementsprotons near to bromine-shifted down|Dividing Pattern| 4. 0 protons – split into a four1. 8 protons-split into four and doublet1. 6 protons- split into doublet1. 0 protons – split into triplet|Integration| 9 Hydrogen|
There were similar displacements in some countries. such as the displacements at 0. 8 ppm and 1. 0 ppm and both the intoxicant and the alkyl halide had displacements far down field near the 4. 0 ppm scope stand foring methylene Hs. Both represented methyl Hs upfield near the 1. 21 ppm scope every bit good. 2-Butanol contains methyl and is frequently referred to as 2-methyl-2-propanol. Gas Chromatography- gas chromatography was used to find the pureness of the sample. The criterions and the sample from the experiment were placed in the tabular array below with the keeping times to find the individuality and pureness of the alkyl halide. 1-bromopropane| 1. 541|
2-bromopropane| 1. 498|1-bromobutane| 1. 713|2-bromobutane| 1. 635|1-bromopentane| 2. 071|Experiment alkyl halide| 1. 636|
The gas chromatography for the alkyl halide in the experiment was about exact with the 2-bromobutane. Since the intimacy of two. the sample could be considered reasonably pure. The country per centum of 1. 636 keeping clip was listed as 95 per centum. with merely a little less than 5 per centum of the country being impure. Physical Properties- the physical belongingss were non the chief beginning for finding the individuality of the alkyl halide and get downing intoxicant because of the usual inaccuracy. nevertheless the consequences for boiling point and denseness proved close to 2-bromobutane and 2-Butanol. The boiling scope from the hebdomad one experiment was 76-118 ?C. which was excessively big of a scope and the alkyl halide had non been wholly purified. However. the boiling point for 2-butanol intoxicant was about 83 ?C. which lies within the scope of the get downing boiling scope. The boiling scope for the merchandise was 87-92 ?C which closely related to boiling point of 2-bromobutane at 91 ?C. The denseness was calculated to 1. 222 g/mL with 2-bromobutane being 1. 255 g/mL.
The denseness of the merchandise was non important in placing the halide because it was excessively closely related with 1-bromopentane as good. Physical belongingss are helpful in finding the individuality of merchandises but are ne’er important plenty to corroborate the individuality of the merchandise. The consequences from the NMR spectrometry. IR spectrometry. and gas chromatography lead to verification of 2-bromobutane as the alkyl halide produced during the permutation reaction.