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please find the purpse, Discussion, conclusion

un 27 Phoenix June 20 8:10 PM a 35AEXPERIMENT 35A Triphenylmethanol PROCEDURE ether MgBr+ C-OH + MgBr(OH) OMgBr 0 Addct Addition of Benzophenone While the phenylmagnesium bromide solution is being heated and stirred under reflux, make a solution of 1.09 g benzophenone in 2 mL of anhrudrous ether in a 5-mL conical vial. Cap the vial until the reflux period is over. Once the Grignard reagent is cooled to room temperature, draw some of the benzophenone solution into the syringe. Add this solution as rapidly (but not all'at once) as possible to the stirred Grignard reagent. Do not add the solution so rapidly that the solution begins to boil. Add the remainder of the benzophenone solution with the syringe. Once the addition has been completed, cool the mixture to room temperature. The solution turns red and then gradually solidifies as the adduct is formed. When stirring is no longer effective, remove the syringe and septum and stir the mixture with a spatula. Rinse the vial that contained the benzophenone solution with about 1 mL of anhydrous ether and add it to the mixture. Remove the reaction flask from the apparatus and cap it. Occasionally stir the contents of this flask. Recap the flask when it is standing to avoid contact with water vapor. The adduct should be fully formed after about 15 minutes. You may stop here. Hydrolysis Add 6.0 ml of 6M hydrochloric acid (dropwise at first) to neutralize the reaction mixture. The acid converts the adduct to triphenylmethanol and inorganic com- pounds (MgX,). Any unreacted magnesium will react with the acid to evolve hy- drogen gas. Use a spatula to break up the solid while adding the hydrochloric acid. You may need to cap the flask and shake it vigorously to dissolve the solid. Because the neutralization procedure evolves heat, some ether will be lost due to evaporation. You should add enough additional ether to maintain at least a 10-mL volume in the upper organic phase. Eventually, you should obtain two distinct 0 2018 Cengage Learning Al Rights Reserved May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. EPERMENT 354 T layers The upper ether layer will contain triphenylmethanol: the lower aqueous hydrochlorie acid layer will contain the inorganic compounds. Make sure you have two distinct liguid layers, with no sign of any solid, before separating the layers. More ether or hydrochloric acid may be added, if necessary, to dissolve any remaining solid Transfer the entire confents of the reaction flask to a small separatory funnel. leaving the stirring bar behind. Use a small amount of ether to ririse the reaction flask and add this ether to the separatory funnel, If some solid material appears or if there are three layers, add more ether and hedrochloric acid to the separa- tory funnel and shake it. Continue adding small portions of ether and hydrochloric acid to the separatory funnel and shake it until evervthing dissolves. In some cases, it may be necessary to add more water instead of hydrochloric acid. Ultimately, you should have two distinct liquid lavers with no sign of any solid, except possi- bly some magnesium, If a small amount of unreactted magnesium metal is present, you will observe bubbles of hydrogen being formed. You may remove the aqueous layer from the separatory funnel even though the magnesium is still producing hydrogen Separation and Drying Drain the lower aqueous laver into a beaker, Pour the remaining ether layer that contains the triphenylmethanol product into a dry Erlenmeyer flask. Pour the aque- ous layer back into the separatory fuunnel and reextract it with 5 mL of ether. Re- move the lower aqueous phase and discard it, Combine the remaining ether phase with the first ether extract. Dry the ether solution with granular anhydrous sodium sulfate (Technique 12, Section 12.9). Evaporation Remove the dried ether solution from the drying agent by decanting it into a small Erlenmeyer flask and rinse the drying agent with more diethyl ether. Evap- orate the solvent in a hood by heating the flask in a hot water bath at about 50°C (use an air or nitrogen stream to aid the evaporation process). After removal of the solvent, an oily solid should be left. This crude mixture contains the desired triphenylmethanol and the by-product, biphenyl. Most of the biphenyl can be re- moved by adding about 3 mL of petroleum ether (30 to 60°C). Petroleum ether is a mixture of hydrocarbons that easily dissolves the hydrocarbon biphenyl and leaves behind the alcohol triphenylmethanol. Do not confuse this solvent with diethyl ether ("ether"). Heat the mixture slightly, stir it, and then cool the mixture to room tempera- ture. Collect the triphenylmethanol by vacuum filtration on a Hirsch funnel and rinse it with small portions of petroleum ether (Technique 8, Section 8.3 and Fig- ure 8.5). Air-dry the solid, weigh it, and calculate the percentage yield of the crude triphenylmethanol (MW- 260.3). 0.L011 Crystallization -t w have Crystallize your entire product from hot isopropyl alcohol in an Erlenmeyér flask using a hot plate as the heating source. Be sure to add the hot alcohol in small por- tions to the crude product. Add the hot solvent until the solid iust dissolves. Then allow the flask to cool slowly. When it has cooled, place the flask in an ice bath to complete the crystallization. Collect the solid on a Hirsch funnel and wash it with a small amount of cold isopropyl alcohol. Set the crystals aside to air-dry. Report the melting point of the purified triphenylmethanol (literature value, 162°C) and recov- ered yield in grams. Submit the sample to the instructor in a properly labeled vial. 02018 Cengage Leaming AllRights Reserved May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part www. Microscale Approach to Organic Laboratory Thchiqus e Pia, Lampenan, Kri, Engel 320 Place all ether solutions in the container for nonhalogenated liquid wastes. Likewise, the mother liquor from the crystallization using isopropyl alcohol (Ex periment 35A) should also be placed in the container for nonhalogenated liquid wastes. PROCEDURE Preparation of the Grignard Reagent: Phenylmagnesium Bromide ether Br+ Mg MgBr Preparation of Glassware All glassware used in a Grignard reaction must be scrupulously dried. Surprisingly large amounts of water adhere to the walls of glassware, even glassware that is apparently dry. For this experiment, make sure all pieces of glassware have been rinsed with acetone and allowed to dry for at least two days. If the eqip been dried in this manner, then it is not necessary to dry the equipment in an oven. Dry the following pieces of equipment before doing this experiment: a 20-mL round- bottom flask, two 5-mL conical vials, a 25-ml. Erlenmeyer flask, a Claisen head, a syringe, and a calibrated Pasteur pipette ((0.5-mL and 1.0-ml. calibration marks) for use in dispensing ether. If, after drying as described, signs of water are still Visible in the apparatus, dry the equipment in an oven. Prepare a drying tube with anhy- drous calcium chloride. Obtain 0.15 g of shiny magnesium turnings and place them in the dry round- bottom flask. Place a small dry magnetic stirring bar into the flask. Assemble the remainder of the apparatus, as shown in the figure. Seal off the open end of the Claisen head with a rubber septum. Formation of the Grignard Reagent Transfer about 10 mL of anhydrous diethyl ether into a dry 25-mL Erlenmeyer flask and stopper the flask. Use the flask tostore your dry ether during the course of this experiment. During the experiment, remove the ether from this flask with a dry calibrated Pasteur pipette. Place 0.70 mL of bromobenzene (MW-157.0) into a preweighed 5-mL coni- cal vial and determine the weight of the material transferred. Add 4.0 mL of an- hydrous ether to the vial and mix the liquids. After the bromobernzene dissolves, withdraw about 0.8 mL of this solution into the syringe and cap the vial. You will need to save the remainder of the bromobenzene/ether solution for later use; recap the vial between uses. After inserting the syringe needles through the rub- ber septum, add 0.8 mL of the bromobenzene solution to the magnesium in the round-bottom flask. Position the apparatus just above the hot plate (about 60°C) and stir the mixture gently to avoid throwing the magnesium onto the side of the flask. You should begin to notice the evolution of bubbles, from the metal surface, which signals that the reaction is starting. It will probably be necessary to heat the mixture to start the reaction. Because ether has a low boiling point (35 C), it may be sufficient to heat the flask by placing it just above the hot plate. Check to see if the bubbling action continues after the apparatus is removed from the heat. The reaction should start, but if you experience difficulty, proceed to the next paragraph. O 2018 Cengsge Learning All Rights Reserved. May not be scarned, copied or duplicated, or posted to a publicly accessible website, in whole or in part Thhmimethanol and Bemaic Acid EXPERIMENT 35 Optional Steps You may need to employ one or more of t following procedures if heating fails to start t reaction. If you are experiencing difficulty, 1 move the syringe and rubber septum. Place dry glass stirring rod into the flask and gent twist the stirring rod to crush the magnesiu against the glass surface. Reattach the rubb septum and again heat the mixture. Repeat t crushing procedure several times, if necessar to start the reaction. If the crushing procedu fails to start the reaction, then add one sma crystal of iodine to the flask. Again, heat th mixture gently. The most drastic action, othe than starting over again, is to prepare a smal sample of the Grignard reagent in a test tube When this reaction is started, it is added to the main reaction mixture in the flask Syringe Coton Rubber septum CaCl Clamp Apparatus postioned above hot plate Stir bar Completing the Grignard Preparation When the reaction has started, you should ob- serve the formation of a brownish-gray, cloudy solution. Remove more of the bromobenzene/ ether solution from the storage vial with the syringe and add the solution slowly over a pe- riod of 15 minutes. Refill the syringe as neces- sary until all the solution has been added to the magnesium metal. It may be necessary to heat the mixture occasionally with the hot plate dur- ing the addition, but if the reaction becomes too vigorous, slow the addition of the bromo- benzene solution and remove the flask from the hot plate. Ideally, the mixture will boil without the application of external heat. If the reflux slows or stops, it is important that you heat the mixture. As the reaction proceeds, you should observe the grad- ual disintegration of the magnesium metal. When all the bromobenzene has been added, place 2.0 mL of anhydrous ether in the vial that originally contained the bro- mobenzene solution, draw it into the syringe, and add the ether to the reaction mixture. Add more anhydrous ether to replace any that is lost during the reflux pe- riod. After a period of about 30 minutes from the beginning of the addition of bro- mobenzene, most or all of the magnesium should have reacted. Cool the mixture to room temperature. As your instructor designates, go to either Experiment 35A or Apparatus for Experiment 35. Experiment 35B. mel pridus Cal limbng reagant

Answer 1

chemical equation tot the Reaction shoon below OHmgBRoH) + In this eadion 1099 d bonzophenone pid mauaular atight benzo Phenone Numben of mdes dBonsophonone used in this reaction ccight Bengophonane mdeaular cocight &usophanon 182.2179/mds 0054 males Vdlume d Bromobaugeve nensiby Bromo banzene = tucight ycwiemL Beomo benzeni used m this Reaction volume at Bromobungene x Donsity 4 Blomo Beugem mdleaular tocight 4 Nembun d mdus 157 02 g/mdl BAomo benzene Blomo benzene rd- 05-0.0066mds 157.029/md ocignt magvesiamm tuouings used o15g moleaular coright mg mdles mg used 24.305 3/mol e-154 E00061 moly 24.805 In the above eaction C.0066 mdls Blomo benzene emd o o06) molus d 0 0059 moy hengophouone Magnasium is sed so Based epon the data the imiting teagent is bensophenone so coc thave to Calaulat xield Penantage based on Banzophenone eotight

Equation d the Raction mg Bro H) TBlo Ho mduaulor cocight 182.2179/md 9/mol 960-3 cocight tiiphenytmethandl Pladuad Theoretial ield = cocight Bongophonone mdicular cotigh teiphonylmatana mduaulor ocight df Bon3ophenon 1 099 x 260.39/mol 15519 182.2119/d the Reaction- 1551g Theotutical yield Actual Eafoimental xield Yield Perantage- Actual eaimental vicld Theoutical Yield OG09 9 1 39.11 % 551g Yield fenanbge d Reaction 89.11