.

Tuesday, December 18, 2018

'Organic Lab 7\r'

'Amanda Jornd Experiment 7- Synthesis and Reactivity of tert-Butyl Chloride Via an SN1 response Introduction/Background: Alkyl halides be compounds in which a halogen ingredient replaces a hydrogen atom of an alkane. Alkyl halides are classified as primary, secondary coil or tertiary depending on the number of alkyl group group radical root substituents directly attached to the carbon attached to the halogen atom. The occasion of this research lab was to properly prepare t-butyl chloride from t-butyl-alcoholic beverage in a concentrated hydrochloric acid.The chemical response descends by means of with(predicate) a nucleophilic refilling, which is when a nucleophile replaces the leaving group in the substrate. In this lab, the hydroxyl group group of t-butyl alcohol is replaced by a chlorine atom. The moveion proceeds through an SN1 mechanism (Weldegirma 38-41). â€Å"A nucleophile is any neutral or uncharged hint with an unshared pair of electrons. In the substi tution reply, the nucleophile donates an electron pair to the substrate, leading to the get upation of a un put ond stick around to the nucleophile, while breaking the existing bond to the leaving group” (Solomons and Fryhle 99-102).The ii grammatical cases of nucleophilic substitution replys, SN1 and SN2, are identified based on whether the divergent step occur simultaneously (SN1) or in twain separate move (SN2). To combine the t-butyl chloride, the t-butyl alcohol goes through an SN1 answer. Also, the nature of the solvent substructure affect which substitution reaction will occur. Polar protic solvents typically privilege SN1 reactions. This is because the SN1 mechanism is carried out(p) in both steps and the polar protic solvent produces both a cation and an anion which are capable of stabilizing the charges on the ions formed during the reaction.Because an SN2 reaction occurs in one step, this is un raiseable; however, the SN2 reactions tend to favor pol ar aprotic solvents. An different factor affecting the type of substitution reaction is the nature of the leaving group. Since the SN1 reactions occur in one step, they generally require an magnificent leaving group and won’t typically run with a poor leaving group. The SN2 reaction also favors excellent leaving groups but stick out run with any type of leaving group because it is run in devil different steps. To synthesize the t-butyl chloride, the t-butyl alcohol goes through an SN1 reaction. Weldegirma 38-41). Mechanism of the preparation of tert-butyl chloride: doable side reaction during the preparation of tert-butyl chloride: Experimental incision/Flow Chart: character reference 1: 60mL separatory move + cooled 15mL of concentrated HCl to 0? C + added 15mL of HCl to separatory funnel + added 5mL tert-butyl alcohol +swirled it without the stopper for 20 proceeding + allow viewpoint until two distinct classs were formed + drained land layer into Erlenm warmhear tednessr flask and saved reasonable close in thorough Layer- in separatory funnel +added 30mL of DI body of water + swirled for a few minutes let stand until two distinct layers formed + drew score degrade layer into Erlenmeyer flask and saved just inclose Organic Layer- in separatory Funnel + added 15mL of 5% atomic number 11 bicarbonate + move with stopper with venting + let stand for a few minutes until two distinct layers formed + drew off inflict layer into Erlenmeyer flask and kept just inclose Organic Layer- in separatory funnel + added 15mL of water + swirled for a couple minutes + let stand until two distinct layers have formed + drew off lower layer into Erlenmeyer flask and kept just incase Organic Layer transferred harvest-home layer into clean/dry 125 mL Erlenmeyer flask + added 1. 5 grams of anhydrous calcium chloride to dry the product +decanted into round bottom flask + added 6 stewing stones + ran through a simple distillation Tert-Butyl Chloride Part 2- screen resistance #1- + added . 1mL tert-butyl chloride from part 1 + added 1mL of NaI + shake while keeping top of raise tobacco pipe with finger + enter time, look, color, etc. banish payoff Test pipe #2- + added . 1mL tert-butyl chloride from part 1 + added 1mL of AgNO3 + shook while holding top of block out tube with finger recorded time, look, color, etc. confirmatory firmness Test Tube # 3- + added . 2mL tert-chloro butane + added 1mL of NaI + shook while holding top of running game tube with finger + recorded time, look, color, etc. Positive extend Test Tube #4- + added . 2mL tert-chloro butane + added 1mL of AgNO3 + shook while holding top of test tube with finger + recorded time, look, color, etc. Negative firmness of purpose hold over of Chemicals: display board of Chemicals 1: Table of Chemicals 1: Chemical Name-| Physical Properties- | Chemical Properties- | Tert-Butyl Alcohol-| M. P. -25-26 ? CB. P. †82-83? CMolecular Weight- 74. 2 g/ groinWater Solubility- miscible| Combustible- noFlammable- yes| Hydrochloric Acid-| M. P. †-114? CB. P. †-85. 05? CMolecular Weight-36. 4 g/mol| Combustible- yesFlammable- no| Sodium bicarbonate-(Chembook) (Chembook) | M. P. †50? CB. P. †851? CMolecular Weight- 84 g/molWater Solubility- 9 g/ vitamin CmL| Combustible- noFlammable-no| Table of Chemicals 2: Table of Chemicals 2: Tert-butyl chloride-| M. P. †-26? CB. P. †51? CMolecular Weight- 92. 57 g/molWater Solubility- meagrely| Combustible- noFlammable-yes| Anhydrous calcium chloride- | M. P. †772? CB. P. †1935?CMolecular Weight- 110. 98 g/molWater Solubility- 74. 5 g/ 100mL| Combustible- yes/ slightlyFlammable- no| Silver nitrate-| M. P. †212? CB. P. †444? CMolecular Weight- 169. 87 g/molWater Solubility- 122 g/100mL| Combustible- noFlammable- no| Sodium iodide-(Chembook) (Chembook) | M. P. †661? CB. P. †1304? CMolecular Weight- 149. 89 g/molWater Solubility- 178. 8 g / 100mL| Co mbustible- noFlammable- no| Table of Chemicals 3: Table of Chemicals 3: 1-chlorobutane- (Chembook) (Chembook) | M. P. †-123? CB. P. †78? CMolecular Weight- 92. 57 g/molWater Solubility- . g/L| Combustible- YesFlammable-Yes| Results: Percent Yield- t-butyl alcohol: constriction = battaliones/Volume : M= . 842 x 5 = 4. 21 grams Mass/ M. W. = # moles : 4. 21 g / 74. 12 g/mol = . 0568 moles of t-butyl alcohol t-butyl chloride: Density = Mass / Volume : M= . 397 x 2 = . 794 grams mass / M. W. = # moles: . 794 g / 92. 57 g/mol = . 00858 moles of t-butyl chloride Because of a 1:1 ratio past you can use actual / theoretical x 100 . 00858 moles / . 0568 moles x 100 = 15. 105 % Results Table 1: Results Table 1: | Color| Precipitate carriage| Time of pass| later on warm water (50?C) toilet| Positive or Negative Result| Test Tube # 1- T-butyl chloride & NaI| Clear/ drop dead tint of yellow| No headlong| all over 6 minutes and still no precipitate| Nothing occurred afte rward 6 minutes in the locomote bath| Negative Result| Test Tube # 2- T-butyl chloride & AgNO3| Cloudy and snow-covered| Yes, pocketable solid particles| . 8 seconds| N/A| Positive Result| Test Tube # 3- t-chloro butane & NaI| middling cloudy with initial drop but speedily turned make it| No precipitate after 6 minutes| 6 minutes RT, for steam bath 4 minutes 58 seconds| yellowish event as well as white precipitate on bottom formed. Positive Result| Test Tube #4- t-chloro butane & AgNO3| Clear pallid liquid| No precipitate| 6 minutes RT, 6 minutes steam bath| No precipitate| Negative Result| Discussion: end-to-end this lab, the main goal was to properly compel a t-butyl chloride. In order to test if we properly acquire our product we tested the sample with two different solvents, a solvent of sodium iodide and silvern nitrate. If an alkyl halide is a tertiary one, it can easily react with a solvent of silver nitrate to cause a relatively stable tertiary carb ocation through an SN1 reaction.If an alkyl halide is a primary one, it can consequently react with iodide ions in the sodium iodide solvent by an SN2 mechanism showing a precipitate of insoluble sodium chloride. Heat can also be use in this process to speed up the reaction (Weldegirma 38-41). The first test we ran was t-butyl chloride and sodium iodine. After mixing the two compounds, thither was only a slight tint to the liquid but remained clear and precipitate free for 6 minutes of world room temperature. We then placed it in a warm water in which there was no precipitate that formed while being heated.This test yielded a negative termination. The second test that we ran was t-butyl chloride and silver nitrate. Directly after mixing the compounds, there was an flying white precipitate that had formed. This test yielded a arbitrary result. A negative result with sodium iodide and a compulsive result of silver nitrate reason out that our solution of t-butyl chloride was a p ure tertiary alkyl halide. Our third test was run with t-chloro butane and sodium iodide. This test initially did not form a precipitate while it was kept at room temperature.We then used a warm water bath in which after 5 minutes the solution formed a white precipitate and a yellow liquid. This shows that this test was a positive test. The fourth test was with t-chloro butane and silver nitrate. This test did not form a precipitate at room temperature or during the steam bath. This shows a negative result. With the t-chloro butane, the negative result with silver nitrate and the positive result of sodium iodide prove that this is indeed a primary alkyl halide. Conclusion:In this lab, we properly carried out an SN1 reaction from t-butyl alcohol to t-butyl chloride and found that we did in fact create a t-butyl chloride by getting a positive result from our silver nitrate test in the end. Although we weren’t able to visibly see with our eye the nucleophilic attack, the steps that we carried out in the lab showed the spaced layers and that there were reactions going on during each step. The ingrained layer that was continuously washed was undergoing the slow reaction process during each separating stage.In the end, after the distillation of the solution, the SN1 reaction was completely carried out. The information from this data has revealed that it is possible to stop out an SN1 reaction in a lab; however, in the process of washing the product there will be a lot of real(a) lost giving a low pct yield in the end. It would be smart to use chemicals that are inexpensive and in large quantities to flow out these types of reactions. The information and techniques performed in this lab could be applied to other situations in an industrial setting.One utilization of this could be creating chlorofluorocarbons which used to be produced for aerosol cans and other products. Although these are no longer widely used in the world due to ozone effect, the SN1 r eaction could be done with these chemicals. Overall, the lab accomplished what it was set out to do. References: â€Å"Chemical Book. ” 2008. <http://www. chemicalbook. com/ProductIndex_EN. asp&xgt;. Solomons, T. W. Graham, and Craig Fryhle. Organic Chemistry. 10th. 1. saucy Jersey: John Wiley & Sons, Inc. , 2011. 99-102. Print. Weldegirma, Solomon. Experimental Organic Chemistry. Mason: Cengage Learning, 2012. 38-41. Print.\r\n'

No comments:

Post a Comment