英文版化学实验报告

Preparationofn-bromobutane一、Purpose1、Studytheprincipleandmethodofpreparingn-butylbromidefromn-butylalcoholbytreatmentwithsodiumbromideandconcentratedsulfuricacid2、Learnthetechniqueofrefluxwithagastrapapparatusandwashing.二、Principlen-Butylbromidecanbeeasilypreparedbyallowingn-butylalcohtoreactwithsodiumbromideandconcentratedsulfuricacid.Mainreactions：NaBr+H2SO4→HBr+NaHSO424HSO322232222CHCHCHCHOHHBrCHCHCHCHBrHOSecondaryreactions：24HSO32223222CHCHCHCHOHCHCHCH=CHHO；24HSO32223222222CHCHCHCHOHCHCHCHCHOHO24222HSOHBrBrSOHO三、Materialsn-butylalcohol：4mLSodiumbromide：5gConcentratedsulfuricacid：2.5mL/6mLAnhydrouscalciumchloride:0.5g10%aqueoussodiumhydroxide:5mL四、PrimaryreagentAndProductphysicalconstantsNameRelativemolecularmassCharacterRelativedensityMeltingpointBoilingpointRefractiveindexn-bromobutane137.03colorlessandtransparentliquid1.299-122.4101.61.4399n-butylalcohol74.12colorlessandtransparentliquid0.8098-89.2117.71.3993五、Apparatus11123456789110234567891101112345678911023456789110六、Procedure（1）50mLboilingflask+50mLwater+6mLconcentratedsulfuricacidCooldown（2）Assemblingequipment(3)Stopandsimpledistill(4)Add4mLn-butylalcohol+5gSodiumbromidebromideRefluxfor30minDistilloffn-bromobutane5mLwaterDistillate（crudeproduct）(5)Dry（CaCl2）七、Experimentalrecords(1)Sulfuricacidsolubleinwatergivesoffalotofheat(2)Thesolutionofthedistillationflaskbecomeyellowandthesodiumbromidedissolve(3)Solutionisdividedintotwolayersandliquidofthedistillationbecomeclear(4)Liquidlayer,upperasthewaterphase,thelowerispositivebromobutaneandliquidforthemilkyhaze(5)Liquidat99℃andstabledistillation,afterrisingto103℃,103℃afterfractionsandtheformerpartofthedon'tmix.八、DatarecordingSolutionwashing2.5mLConcentratedsulfuricacid5mLwater5mL10%aqueoussodiumhydroxide5mLwaterDry（CaCl2）Distill（99-103℃）WeightandyieldRefractiveindexOutput:1.3gtheoreticalyield:5.8gproductivity:21.7%Character:colorlessandtransparentliquidRefractiveindex:1.4372九、ExperimentDiscussion1、Turbidityisbecauseitcontainsavarietyoforganicphasetoorganicimpurities2、Plusthebottlestopperofcalciumchlorideanhydrousdrybatteryinordertopreventthewatervaporintheairintotheconicalflask,atthesametimepreventproductturbidity