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Unformatted text preview: Danielle​ ​Tavares Melissa​ ​Bornico Lab​ ​#2 Acid​ ​and​ ​Base​ ​Extraction Chemistry​ ​335-A59 Introduction:​​ ​An​ ​acid-base​ ​extraction​ ​is​ ​a​ ​type​ ​of​ ​liquid-liquid​ ​extraction.​ ​It​ ​typically​ ​involves​ ​different solubility​ ​levels​ ​in​ ​water​ ​and​ ​an​ ​organic​ ​solvent.​ ​Acid-base​ ​extraction​ ​is​ ​typically​ ​used​ ​to​ ​separate​ ​organic compounds​ ​from​ ​each​ ​other​ ​based​ ​on​ ​their​ ​acid-base​ ​properties.​​ ​The​ ​melting​ ​points​ ​of​ ​the​ ​unknown​ ​acid,​ ​base and​ ​neutral​ ​will​ ​be​ ​used​ ​to​ ​determine​ ​the​ ​identity​ ​of​ ​the​ ​compounds.​ ​The​ ​melting​ ​point​ ​is​ ​the​ ​phase​ ​change​ ​at which​ ​a​ ​solid​ ​turns​ ​into​ ​a​ ​liquid.​ ​Melting​ ​point​ ​is​ ​used​ ​as​ ​a​ ​way​ ​to​ ​determine​ ​the​ ​temperature​ ​this​ ​phase​ ​change occurs​ ​which​ ​aids​ ​in​ ​compound​ ​identification​ ​and​ ​to​ ​estimate​ ​purity.​ ​Generally,​ ​a​ ​range​ ​of​ ​less​ ​than​ ​2o​​ ​ ​is acceptable​ ​for​ ​a​ ​given​ ​compound​ ​to​ ​be​ ​considered​ ​pure.​ ​A​ ​melting​ ​point​ ​determination​ ​utilizes​ ​a​ ​SRS​ ​DigiMelt 160​ ​melting​ ​point​ ​apparatus​ ​that​ ​determines​ ​the​ ​melting​ ​points​ ​of​ ​small​ ​samples.​ ​The​ ​key​ ​things​ ​to​ ​remember are​ ​not​ ​using​ ​large​ ​samples,​ ​always​ ​using​ ​a​ ​new​ ​capillary​ ​tube,​ ​and​ ​not​ ​rapidly​ ​heating​ ​the​ ​sample. Technique​ ​2.3: ● Obtain​ ​a​ ​Büchner​ ​funnel​ ​to​ ​do​ ​a​ ​vacuum​ ​filtration. ● Crystals​ ​should​ ​be​ ​rinsed​ ​with​ ​small​ ​amounts​ ​of​ ​cold​ ​solvent. ● Crystals​ ​were​ ​dried​ ​using​ ​suction​ ​filtration,​ ​and​ ​air​ ​drying. Technique​ ​3.0: ● Ensure​ ​that​ ​the​ ​stopcock​ ​to​ ​the​ ​separatory​ ​funnel​ ​is​ ​closed.​ ​As​ ​a​ ​safety​ ​measure,​ ​place​ ​a​ ​beaker underneath​ ​the​ ​funnel​ ​in​ ​case​ ​it​ ​leaks ● As​ ​the​ ​organic​ ​solvent​ ​and​ ​water​ ​are​ ​not​ ​miscible​ ​with​ ​each​ ​other,​ ​the​ ​two​ ​layers​ ​(organic​ ​and​ ​aqueous layers)​ ​should​ ​be​ ​seen​ ​clearly.​ ​Two​ ​separately​ ​labeled​ ​beakers​ ​should​ ​be​ ​ready. ● To​ ​remove​ ​all​ ​inorganic​ ​substances​ ​from​ ​the​ ​organic​ ​layer,​ ​shake​ ​the​ ​separatory​ ​funnel​ ​to​ ​increase​ ​the contact​ ​between​ ​these​ ​substances​ ​and​ ​the​ ​water.​ ​The​ ​proper​ ​way​ ​to​ ​hold​ ​a​ ​separatory​ ​funnel​ ​is​ ​to​ ​grasp the​ ​funnel​ ​so​ ​that​ ​the​ ​stopper​ ​is​ ​in​ ​the​ ​palm​ ​of​ ​one​ ​hand​ ​the​ ​stopcock​ ​is​ ​held​ ​with​ ​the​ ​other. ● After​ ​a​ ​few​ ​shakes,​ ​hold​ ​the​ ​funnel​ ​upside​ ​down​ ​with​ ​the​ ​funnel​ ​stem​ ​pointed​ ​away​ ​from​ ​nearby​ ​people, and​ ​open​ ​the​ ​stopcock​ ​to​ ​release​ ​any​ ​pressure. ● Close​ ​the​ ​funnel​ ​and​ ​shake​ ​the​ ​funnel​ ​a​ ​little​ ​more​ ​vigorously​ ​and​ ​vent​ ​again​ ​as​ ​necessary. ○ This​ ​"shake​ ​and​ ​vent"​ ​method​ ​can​ ​be​ ​repeated​ ​two​ ​or​ ​three​ ​times​ ​as​ ​needed. ● When​ ​finished,​ ​the​ ​funnel​ ​can​ ​be​ ​returned​ ​to​ ​the​ ​ring​ ​stand​ ​and​ ​the​ ​layers​ ​allowed​ ​to​ ​separate. ● At​ ​this​ ​point​ ​the​ ​two​ ​layers​ ​can​ ​be​ ​separated​ ​into​ ​their​ ​respective​ ​beakers. Procedure: 1. ​ ​A​ ​60​ ​ml​ ​separatory​ ​funnel​ ​was​ ​obtained​ ​and​ ​15​ ​ml​ ​of​ ​distilled​ ​water,​ ​2.5ml​ ​concentrated​ ​hydrochloric acid​ ​and​ ​15​ ​ml​ ​of​ ​ether​ ​were​ ​added. 2. 1.30g​ ​of​ ​solid​ ​extraction​ ​was​ ​obtained​ ​and​ ​added​ ​it​ ​to​ ​the​ ​separatory​ ​funnel. 3. A​ ​stopper​ ​was​ ​placed​ ​in​ ​the​ ​funnel​ ​and​ ​was​ ​gently​ ​shaken. a. Occasionally​ ​the​ ​funnel​ ​was​ ​vented​ ​by​ ​opening​ ​the​ ​stopcock​ ​and​ ​tilting​ ​it​ ​from​ ​underneath​ ​the hood​ ​and​ ​away​ ​from​ ​the​ ​glass. b. Step​ ​3a​ ​was​ ​repeated​ ​until​ ​all​ ​solids​ ​were​ ​dissolved. 4.​ ​The​ ​funnel​ ​was​ ​placed​ ​on​ ​a​ ​ring​ ​stand​ ​and​ ​the​ ​layers​ ​were​ ​left​ ​to​ ​settle. 5.​ ​The​ ​stopper​ ​was​ ​removed​ ​before​ ​opening​ ​the​ ​stopcock​ ​and​ ​the​ ​lower​ ​layer​ ​of​ ​solution​ ​was​ ​drained​ ​off into​ ​a​ ​CLEAN​ ​flask. 6.​ ​Steps​ ​3-5​ ​were​ ​repeated​ ​by​ ​adding​ ​another​ ​5​ ​ml​ ​of​ ​distilled​ ​water​ ​and​ ​2.5ml​ ​concentrated​ ​hydrochloric acid. 7.​ ​To​ ​the​ ​remaining​ ​ether​ ​solution​ ​in​ ​the​ ​separatory​ ​funnel,​ ​8​ ​ml​ ​of​ ​sodium​ ​bicarbonate​ ​was​ ​slowly​ ​added. 8.​ ​Once​ ​again​ ​the​ ​mixture​ ​was​ ​shaken​ ​gently​ ​while​ ​relieving​ ​pressure. a. It​ ​was​ ​then​ ​drained​ ​into​ ​a​ ​second​ ​erlenmeyer​ ​flask. b. Steps​ ​7-8​ ​were​ ​repeated​ ​until​ ​the​ ​aqueous​ ​solutions​ ​tested​ ​basic. 9.​ ​The​ ​remaining​ ​solution​ ​(neutral​ ​substance)​ ​was​ ​poured​ ​into​ ​a​ ​clean​ ​erlenmeyer​ ​flask. 10.​ ​One​ ​spatula​ ​full​ ​of​ ​a​ ​drying​ ​agent​ ​was​ ​added​ ​to​ ​the​ ​neutral​ ​substance​ ​and​ ​swirled. a. Clumping​ ​occurred​ ​at​ ​first​ ​so​ ​more​ ​of​ ​the​ ​drying​ ​agent​ ​was​ ​added​ ​until​ ​it​ ​became​ ​granular​ ​in appearance. 11.​ ​ ​The​ ​liquid​ ​from​ ​neutral​ ​substance​ ​was​ ​poured​ ​out​ ​into​ ​a​ ​clean​ ​beaker. 12.​ ​The​ ​drained​ ​solution​ ​was​ ​put​ ​in​ ​a​ ​warm​ ​water​ ​bath​ ​in​ ​a​ ​hood. 13.​ ​To​ ​the​ ​flask​ ​containing​ ​the​ ​base,​ ​add​ ​hydrochloric​ ​acid​ ​was​ ​added​ ​with​ ​a​ ​dropper​ ​until​ ​a​ ​substrate formed. a. Mixture​ ​was​ ​then​ ​put​ ​into​ ​an​ ​ice​ ​bath. 14.​ ​Step​ ​13​ ​was​ ​repeated​ ​with​ ​the​ ​acid​ ​and​ ​sodium​ ​hydroxide. 15.​ ​Filter​ ​crystals​ ​and​ ​determine​ ​melting​ ​point. 16.​ ​While​ ​samples​ ​were​ ​cooling,​ ​the​ ​suction​ ​filtration​ ​was​ ​set​ ​up​ ​using​ ​a​ ​Büchner​ ​funnel​ ​and​ ​flask​ ​and​ ​two pieces​ ​of​ ​filter​ ​paper. a. The​ ​suction​ ​filtration​ ​was​ ​tested​ ​before​ ​use​ ​by​ ​turning​ ​on​ ​the​ ​water​ ​and​ ​feeling​ ​for​ ​the​ ​suction through​ ​the​ ​tube. 17.​ ​Once​ ​the​ ​mixture​ ​was​ ​cool,​ ​it​ ​was​ ​filtered​ ​through​ ​the​ ​Büchner​ ​funnel​ ​using​ ​vacuum​ ​filtration. 18.​ ​The​ ​crystals​ ​were​ ​then​ ​rinsed​ ​out​ ​of​ ​the​ ​original​ ​Erlenmeyer​ ​flask​ ​using​ ​distilled​ ​water. a. The​ ​crystals​ ​are​ ​rinsed​ ​several​ ​more​ ​times​ ​to​ ​ensure​ ​there​ ​are​ ​as​ ​few​ ​impurities​ ​as​ ​possible remaining. 19.​ ​The​ ​product​ ​was​ ​then​ ​dried​ ​using​ ​vacuum​ ​filtration. 20.​ ​Once​ ​dry​ ​the​ ​product​ ​was​ ​weighed​ ​and​ ​a​ ​small​ ​sample​ ​of​ ​the​ ​unknown​ ​crystal​ ​was​ ​taken​ ​and​ ​run through​ ​the​ ​DigiMelt​ ​process. 21.​ ​The​ ​acid,​ ​base​ ​and​ ​neutral​ ​substances​ ​had​ ​melting​ ​points​ ​of​ ​116.4​o​C,​ ​80.5​o​C,​ ​and​ ​77.9​o​C​ ​respectively. This​ ​lead​ ​to​ ​the​ ​conclusion​ ​that​ ​the​ ​unknown​ ​samples​ ​were​ ​Benzoic​ ​Acid,​ ​Ethyl-4-aminobenzoate,​ ​and Naphthalene​ ​respectively. Data: Name​ ​(Acids) Structure Appearance Molecular Weight ​ ​Colorless crystals ​ ​122.12 g/mol ​ ​Light​ ​brown solid ​ ​156.57 g/mol Boiling Point (​o​C) ​​ Melting Point (​o​C) Solubility in​ ​Water ​ ​p-t-Butylbenzoic Acid ​ ​White powder ​ ​178.23 g/mol Harmful​ ​if swallowed Can​ ​cause​ ​skin irritation,​ ​eye irritation,​ ​eye damage,​ ​organ damage​ ​with prolonged​ ​exposure. 249.2 ​ ​122 2.7g/L (18​o​C) Sublimes 142 <1mg/ mL (20​​ ​o​C) Harmful​ ​if swallowed. Can​ ​cause​ ​skin irritation and​ ​eye​ ​irritation. ​ ​Insoluble Harmful​ ​if swallowed.​ ​Can cause​ ​organ​ ​damage and​ ​fertility damage. Benzoic​ ​Acid ​ ​O-Chlorobenzoic Acid Safety N/A 165 4-Nitrobenzoic Acid Light​ ​yellow powder 167.12 g/mol Sublimes 237 <0.1g/ 100mL (26​​ ​o​C) White crystals 165.19 g/mol 310 92 N/A Yellow​ ​solid 138.14 g/mol 306 114 0.1g/ 100mL (20​​ ​o​C) Combustible. Harmful​ ​if swallowed,​ ​in contact​ ​with​ ​skin, inhaled.​ ​Can​ ​cause eye​ ​and​ ​respiratory tract​ ​irritation. Bases Ethyl-4-aminobenzoate m-Nitroaniline 4-Nitroaniline 2,4-Dinitroaniline Neutral Yellow /brown powder Colorless​ ​to yellowish powder 138.12 g/mol 183.12 g/mol 332 57 147 177 0.8mg/ mL (18.5​​ ​o​C) 1-2g/L (20​​ ​o​C) Can​ ​cause​ ​allergic skin​ ​reactions​ ​and organ​ ​damage. Combustible.​ ​Toxic if​ ​swallowed,​ ​in contact​ ​with​ ​skin, inhaled​ ​and​ ​can cause​ ​organ damage. Combustible.​ ​Toxic if​ ​swallowed,​ ​in contact​ ​with​ ​skin, inhaled​ ​and​ ​can cause​ ​organ damage. Combustible​ ​when exposed​ ​to​ ​heat​ ​or flames.​ ​Fatal​ ​if swallowed,​ ​in contact​ ​with​ ​skin,​ ​if inhaled​ ​and​ ​can cause​ ​organ damage. Naphthalene 9-Fluorenone Anthracene White​ ​solid Yellow​ ​solid Colorless 128.17 g/mol 180.21 g/mol 178.23 g/mol Unknown​ ​Sample​ ​# Weight​ ​of​ ​Unknown​ ​Sample​ ​(g) Amount​ ​of​ ​HCl​ ​Added​ ​(mL) Amount​ ​of​ ​NaOH​ ​Added​ ​(mL) Identity​ ​of​ ​Sample 218 342 340 80 84 216 7 1.30g 10mL 17mL Naphthalene Unknown​ ​Neutral​ ​(Naphthalene)​ ​DigiMelt Actual​ ​Melting​ ​Point​ ​from 80 Handbook Melting​ ​Point​ ​Range 77-78.8​o​C Melting​ ​Point​ ​of​ ​Unknown 77.9​o​C Temperature​ ​Difference 2.1​o​C Apparatus​ ​Used 1 Percent​ ​Recovery 26.6% The​ ​DigiMelt​ ​apparatus​ ​was​ ​set​ ​at​ ​a​ ​range​ ​of​ ​70-90​ ​and​ ​a​ ​ramp​ ​rate​ ​of​ ​2. Unknown​ ​Acid​ ​(Benzoic​ ​Acid)​ ​DigiMelt Actual​ ​Melting​ ​Point​ ​from 122.4​o​C Handbook Melting​ ​Point​ ​Range 115.-117.8​o​C Measured​ ​Melting​ ​Point 116.4​o​C Temperature​ ​Difference 6.0​o​C Apparatus​ ​Used 1 Percent​ ​Recovery 19.2% The​ ​DigiMelt​ ​apparatus​ ​was​ ​set​ ​at​ ​a​ ​range​ ​of​ ​115-175​ ​and​ ​a​ ​ramp​ ​rate​ ​of​ ​2. 31.6mg/ L (25​​ ​o​C) Insoluble 0.044mg/ L (25​​ ​o​C) Combustible​ ​above 80​o​C.​ ​Harmful​ ​if swallowed.​ ​Can cause​ ​allergic​ ​skin reactions,​ ​eye irritation,​ ​cancer and​ ​organ​ ​damage. Can​ ​cause​ ​skin,​ ​eye, and​ ​respiratory irritation. Combustible.​ ​Fatal if​ ​swallowed.​ ​Can cause​ ​skin irritations,​ ​allergic skin​ ​reactions, cancer​ ​and​ ​fertility damage. Unknown​ ​Base​ ​(Ethyl-4-aminobenzoate)​ ​DigiMelt Actual​ ​Melting​ ​Point​ ​from 89​o​C Handbook Melting​ ​Point​ ​Range 79.8-81.2​o​C Measured​ ​Melting​ ​Point 80.5​o​C Temperature​ ​Difference 8.5​o​C Apparatus​ ​Used 1 Percent​ ​Recovery 27.7% The​ ​DigiMelt​ ​apparatus​ ​was​ ​set​ ​at​ ​a​ ​range​ ​of​ ​110-140​ ​and​ ​a​ ​ramp​ ​rate​ ​of​ ​2. Mechanism: Observations: The​ ​unknown​ ​crystals​ ​used​ ​in​ ​the​ ​experiment​ ​were​ ​originally​ ​white.​ ​When​ ​performing​ ​the acidification/basification​ ​portion​ ​of​ ​the​ ​lab,​ ​the​ ​solution​ ​changed​ ​color​ ​and​ ​appearance​ ​when​ ​either​ ​the​ ​base​ ​was added​ ​to​ ​the​ ​acid,​ ​or​ ​in​ ​the​ ​second​ ​case​ ​when​ ​the​ ​acid​ ​was​ ​added​ ​to​ ​the​ ​base.​ ​This​ ​was​ ​due​ ​to​ ​a​ ​crystal precipitate​ ​forming.​ ​The​ ​final​ ​appearances​ ​of​ ​the​ ​two​ ​crystals​ ​differed.​ ​The​ ​base​ ​products​ ​was​ ​more​ ​crystallized while​ ​the​ ​acid​ ​product​ ​looked​ ​more​ ​like​ ​a​ ​powder. Calculations: pure product recovered (acid) (g) pure product recovered (base) (g) pure product recovered (neutral) (g) P ercent Recovery = Amount + Amount + AmountAmount * 100 Amount crude material used (g) Amount crude material used (g) crude material used (g) P ercent Recovery = .25 (g) 1.30 (g) + .36 (g) 1.30 (g) + .346 (g) 1.30 (g) * 100 = 73.50% Discussion/Conclusion: An​ ​acid-base​ ​extraction​ ​is​ ​a​ ​type​ ​of​ ​liquid-liquid​ ​extraction.​ ​It​ ​typically​ ​involves​ ​different​ ​solubility​ ​levels​ ​in water​ ​and​ ​an​ ​organic​ ​solvent.​ ​Acid-base​ ​extraction​ ​is​ ​typically​ ​used​ ​to​ ​separate​ ​organic​ ​compounds​ ​from​ ​each other​ ​based​ ​on​ ​their​ ​acid-base​ ​properties.​ ​The​ ​method​ ​rests​ ​on​ ​the​ ​assumption​ ​that​ ​most​ ​organic​ ​compounds​ ​are more​ ​soluble​ ​in​ ​organic​ ​solvents​ ​than​ ​they​ ​are​ ​in​ ​water.​ ​The​ ​neutral​ ​compound​ ​does​ ​not​ ​react​ ​with​ ​any​ ​acids​ ​or bases.​ ​General​ ​steps​ ​for​ ​extraction​ ​that​ ​were​ ​followed​ ​within​ ​this​ ​lab​ ​were: Technique​ ​3.0: ● Ensure​ ​that​ ​the​ ​stopcock​ ​to​ ​the​ ​separatory​ ​funnel​ ​is​ ​closed.​ ​As​ ​a​ ​safety​ ​measure,​ ​place​ ​a​ ​beaker underneath​ ​the​ ​funnel​ ​in​ ​case​ ​it​ ​leaks ● As​ ​the​ ​organic​ ​solvent​ ​and​ ​water​ ​are​ ​not​ ​miscible​ ​with​ ​each​ ​other,​ ​the​ ​two​ ​layers​ ​(organic​ ​and​ ​aqueous layers)​ ​should​ ​be​ ​seen​ ​clearly.​ ​Two​ ​separately​ ​labeled​ ​beakers​ ​should​ ​be​ ​ready. ● To​ ​remove​ ​all​ ​inorganic​ ​substances​ ​from​ ​the​ ​organic​ ​layer,​ ​shake​ ​the​ ​separatory​ ​funnel​ ​to​ ​increase​ ​the contact​ ​between​ ​these​ ​substances​ ​and​ ​the​ ​water.​ ​The​ ​proper​ ​way​ ​to​ ​hold​ ​a​ ​separatory​ ​funnel​ ​is​ ​to​ ​grasp the​ ​funnel​ ​so​ ​that​ ​the​ ​stopper​ ​is​ ​in​ ​the​ ​palm​ ​of​ ​one​ ​hand​ ​the​ ​stopcock​ ​is​ ​held​ ​with​ ​the​ ​other. ● After​ ​a​ ​few​ ​shakes,​ ​hold​ ​the​ ​funnel​ ​upside​ ​down​ ​with​ ​the​ ​funnel​ ​stem​ ​pointed​ ​away​ ​from​ ​nearby​ ​people, and​ ​open​ ​the​ ​stopcock​ ​to​ ​release​ ​any​ ​pressure. ● Close​ ​the​ ​funnel​ ​and​ ​shake​ ​the​ ​funnel​ ​a​ ​little​ ​more​ ​vigorously​ ​and​ ​vent​ ​again​ ​as​ ​necessary. ○ This​ ​"shake​ ​and​ ​vent"​ ​method​ ​can​ ​be​ ​repeated​ ​two​ ​or​ ​three​ ​times​ ​as​ ​needed. ● When​ ​finished,​ ​the​ ​funnel​ ​can​ ​be​ ​returned​ ​to​ ​the​ ​ring​ ​stand​ ​and​ ​the​ ​layers​ ​allowed​ ​to​ ​separate. ● At​ ​this​ ​point​ ​the​ ​two​ ​layers​ ​can​ ​be​ ​separated​ ​into​ ​their​ ​respective​ ​beakers. Within​ ​experiments​ ​there​ ​are​ ​many​ ​sources​ ​of​ ​error​ ​that​ ​could​ ​take​ ​place.​ ​Within​ ​the​ ​extraction​ ​period,​ ​if​ ​the funnel​ ​is​ ​shaken​ ​to​ ​gently​ ​than​ ​there​ ​will​ ​not​ ​be​ ​an​ ​effective​ ​mixing​ ​of​ ​the​ ​two​ ​phases,​ ​shaking​ ​the​ ​separatory funnel​ ​vigorously​ ​sometimes​ ​leads​ ​to​ ​emulsion.​ ​Neutralisation​ ​with​ ​HCl​ ​happens​ ​in​ ​two​ ​separate​ ​stages. The​ ​first​ ​reaction​ ​occurs​ ​when​ ​equimolar​ ​amounts​ ​of​ ​reactants​ ​are​ ​added​ ​together,​ ​producing​ ​sodium bicarbonate​ ​and​ ​sodium​ ​chloride.​ ​As​ ​more​ ​HCl​ ​is​ ​added​ ​the​ ​sodium​ ​bicarbonate​ ​reacts​ ​with​ ​it​ ​to​ ​produce​ ​CO2, NaCl​ ​and​ ​H2O.​ ​Not​ ​adding​ ​enough​ ​would​ ​disrupt​ ​this​ ​process.​ ​The​ ​NaCl​ ​is​ ​also​ ​what​ ​was​ ​seen​ ​on​ ​the​ ​tip​ ​of​ ​the funnel​ ​and​ ​surface​ ​of​ ​the​ ​aqueous​ ​solution.​ ​If​ ​not​ ​enough​ ​HCl​ ​or​ ​NaOH​ ​are​ ​added​ ​then​ ​the​ ​crystal​ ​will​ ​not​ ​fully precipitate​ ​out​ ​of​ ​solution.​ ​Without​ ​an​ ​ice​ ​water​ ​bath,​ ​then​ ​the​ ​full​ ​amount​ ​of​ ​crystal​ ​would​ ​not​ ​have precipitated​ ​out​ ​and​ ​there​ ​would​ ​have​ ​been​ ​ ​a​ ​lower​ ​percent​ ​recovery.​ ​The​ ​organic​ ​solvent​ ​containing​ ​the neutral​ ​compound​ ​contains​ ​some​ ​dissolved​ ​water.​ ​Adding​ ​a​ ​solid​ ​inorganic​ ​drying​ ​agent​ ​is​ ​done​ ​and​ ​then​ ​the solvent​ ​can​ ​then​ ​be​ ​removed​ ​by​ ​evaporation,​ ​leaving​ ​behind​ ​the​ ​solid​ ​neutral​ ​compound. Acknowledgements: Melissa​ ​Bornico Angel​ ​Zhang References: Pubchem Chem.UMass.edu ...
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