LabManual - Chemistry 118 C. Preliminary Lab Report Sheet...

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Unformatted text preview: Chemistry 118 C. Preliminary Lab Report Sheet (To be filled out before coming to the laboratory and turned in before stam'ng the experiments) Dale: N Student's Name: _____'_____-________________.__————‘_~ Locker Number: T.A.'s Name: ________________________ TITLE OF EXPERIMENT PROPERTIES OF BEAGENTS, SOLVENTS.AND PRODUCTS. Name .______._—__——‘——-—I-——I——-—_ ___________._______——————-——-—-—- M.W. M.P.,°C B.P.,°C ' Density EQUATIONS FOR MAIN REACTIONS LIMITING REAGENT IN THE PROCEDURE SPECIAL SAFETY OR TOXICITY PROBLEMS EXPECTED __________________________'_________________———-—v——-—- ____'__________________________________.__——~————- “MM 11 Expt. I: Synthesis I of Benzocaine O OH O \c/ _ ‘ ~OCH2CH3 “O .NH, NH, 9.41111an «:44 EIhyI(g-:nl:lmhn)zmo eferenc : "Introduction to Organic Laboratory Techniques", P, L, K & E, 3rd Ed., p L_._e_ "Organic Chemistry" Vollhardt and Schore,_~4"' BEL, p 832-834. + H20 ! 1. Sulfuric Acid is a strong, highly egrrosivg ' . 2. Benzocaine may cause dermatitis 1n sensmve mdxmduals. Egoperties of Starting Mata-jails and Ezogucts (From Aldrich Catalog - Handbook) to ass-4 #Amlnobomlc scum-I. 150-1 n uLco‘u M 137.14 1mm... ' t «1.374 non, 14.414 Fun; afflad’fiu 11:04 NAM 2:23.195": 2:3: 57-”? “an” Salary 2.1383 RTECSI oauooooo DI”. A IRRITANT 1kg 27.0744 Ethyl alcohol. tangent. donltuM.HPLC and4 [64-176] (animal) 1 at c.H.OH Fw 40.01 mp 430? up 70' a. 1.3600 4 0.?“ Fa “'fll'q Huck Index 11.37" mm 10.1013 F740 1mm Saluy 2.15!“ I: RTECSI mm mm. D HIGHLY rox1c FUMIJABLE LIQUID i g t: §§:§ me: . ° 7664-93- H muonémo an4.__.'..1oomt 33"": 355‘! 1.347 21.4“ 'sg'm mm um 500ml; arses- wssaooooo DI». N , mautr ram: OXIDIZEII ‘ Hm. cont-M “It . 25.310-5 sumac ncld. 1mm. 4.0.3. nlalnt [7404-93-91 man. 50091 11.2959 Ethyl Hmlnobonzoata,98% [94.097] H.Nc.H.oo.c.H. mem Inna-ML...— sg * BOII.14.4n Muck,Indox11.3719 FF”? 1 303A SI 8 SDI flw1m1911J RTECS' 062450000 Imam mo. drawn“ . I :88: 12 0.1 5 16.85 41.70 .5" 350—352; §'3'_ KPN/98 Procedure: Place 0.25 g of p-aminobenzoic acid and 2.5 ml of absolute ethanol into a 10 ml round- bottom flask. Add a stir bar and stir the mixture until the solid dissolves completely. With stining, add 0.3 ml of conc. H2804 dropwise, with cautign. A large amount of precipitate will form when the H2804 is added, but this solid will slowly dissolve during the reflux that follows. ' Attach a water-cooled condenser (apply a light coating of to-the standard taper joint) and heat the mixture , with stirring, at vigorous reflux for 1 hour, with the heat knOb set around 2-3. When the refluxing begins, you will see vapors condense and liquid flow down on the inner wall of the lower part of the condenser. At the end of the reflux time, remove the apparatus from the heating plate and allow the reaction mixture to cool for several minutes. Using a Pasteur pipet, transfer the reaction mixture to a 25 mL Erlenmeyer flask containing 6.0 mL of water._ While frequently swirling or stirring, add 10% potassium carbonate solution MS; to neutralize the mixture (Caution! As the K2CO3 solution is added, extensive gas evolution (C02) will occur until the mixture is nearly neutralized). During the neutralization the benzocaine will precipitate as a white solid. When gas evolution is no longer observed on adding a drop of the K2C03 solution, check the pH of the solution. When gas no longer evolves, check the pH of the solution. Continue to add K2C03 dropwise until the pH is about 8. . . Collect the benzocaine by suction filtration on a small Hirsch funnel. Use three 2-ml portions of H20 to aid in the transfer and to wash the product in the funnel. Make sure that the solid is rinsed thoroughly with H20. After the product has dried, weigh it, calculate the percent yield, and determine its melting point. The product may be further purified by recrystallization from minimum amount of hot water. Questions: 1. Explain why the amino group of p-aminobenzoic acid does not participate in the reaction. ' ' ' ' ' , 2'. Explain why benzocaine precipitates out during the neutralization. 3 Show the mechanism for esterification reaction. 13 . KPN/98 V$1NIOBHQWd 2mm 0 m 2mm om.l Oh . mo.m 20mm 20\2Lm ommn. 20\NI om.hm_ . "u4<om FOAL F. h¢ n zH<o N: wwow flIHQHB ommm NI: ommwn_.con fl >ozunommu uu>mummo mam Fm n uk<m szm NI on. n ozo<omm quu ochwn fl MNHm <h<o mp fl .mco< Lo .02 0mm F~.n I mZHH mgo>omm 0mm N~.~ I MZHP .OU< mummuuo mm H oum: oo.n fl Ihous mMJDL mozmaomw mmADL mzo 2L! umOH<mumo ngooo\m2H<UOszm mmm<z©o ©>—.me .oomlmo _ mzz we E?” ...-§ an E. .95 .38 9533 65. .65 3.33:... .o seen... 25.... _ H. :— a: 14. KPN/98 21m .0 cm oo_ om_ 2mm NF.m~u oh mo.mp~ zomm zoxzmm nvn~.~w a zuxN: ¢~.¢~m m "555 HoJL a m 33 n 530.. N 2;; con.n— u >ozm=ouzm N 2023282 eolomézfim "6:288 e. um I zH<u N: ooocu uxhnas uumm ~12 +~ooo¢.np n »u2uaouzu Hu>zmwmo mam N” n uh<m szm N: oo.F I oza<omm “2H4. oopun u MNHm <h<o _mwn n .moo< no .oz cum .m.r u quh “40>omm cum: o~.m,o u quh .au< mummoua on a cum: co.» n :Pous um4=m muzmacum mm43m uzo 2;! H52on nJQQoxqu<oo~zum nvmvm 15 KPN/98 Chem 118 C Spectroscopy Practice Problems / Nambiar~ Molecular Formula: C9H1002. 1R Spectrum: Strong absorption bands at 3100 cm'1 , 2950 cm ‘1 , 1735 cm‘1 and 1650 cm 41 it Molecular Formula: C9H1102N . IR Spectrum; A broad band at 3450 cm4v Strong absorption bands; at 3100 cm“1 , . 2955 cm '1 , 1735 cm '1 and 1650 om'1 . =/ 7- Molecular Formula: C4H602. IR Spectrum: Strong absorption bands at 2950 cm'1 and 1735 cm‘1 . ’umummmam Molecuiar Formula: C3H302. IR Strong absorption bands at 3100 cm '1 , 2950 cm ‘1 , 1735 cm‘.1 and 1650 cm‘1 . ~ 'uumsrécmuuwm_m _————————————_——————————— 2 2 3 _ 1 ' l~ ’ fl " ..______._____.__..... ~ 9 3 7 6 '5 ll 4 3 2 I o 601be >- doublet of (1wa doublet "‘ doublet of doublet ‘ 69 ...
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LabManual - Chemistry 118 C. Preliminary Lab Report Sheet...

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