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1、氯化物的重量分析法Gravimetric Analysis of ChlorideIntro ductioiiGravimetric analysis is a method for determining the amount of a chemical present by converting it, through a chemical reaction, into another of known chemical composition, which can be isolated and weighed.In this experiment we will determine t
2、he composition of an unknown chloride salt fXCl)? by reacting chloride and silver ions to produce a silver chloride precipitate. The silver chloride is then filtered out and weighed. Based on the known stoichiometnc ratios of the silver chlonde reaction 1:1 we can determine the amount of chloride in
3、itially present in our metal sample.Ag+ (aq) + Cl- (aq) - AgCl(s)We will begin our experiment by first adding a weighed sample of our unknown XC1 sample to water, the XC1 will disassociate in the water into Cl- and X+ 10ns:XC1 (s)+ HzO (aq) - X+ (aq) +Cl (aq) + HzO (aq)A IM solution of AgN03 is adde
4、d to serve as the source for our Ag+ ions, as AgN03 is added AgCl will precipitate out of the solution. AN03 is added until nomore AgCl precipitates out of solution, the initial quantity of Cl- ions present serves as the limiting agent to our reaction. The amount of excess AgN03 added is not importa
5、nt as once all of the AgCl. We then filter out our AgCl precipitate, and weigh it.From the mass of our AgCl precipitate we can determine how many moles of AgCl were produced:Moles of AgCl = weight of AgCl/ GMW of AgCl = weight of AgCl / 143.32We can determine the % of Cl- present in are unknown:Mole
6、s of Cl- = moles of AgClWeight of Cl- in XC1 sample = (moles of Cl_)x(atomic weight ofCl- = 35.4527)% Cl- in sample = (weight of Cl- in XC1 sample / weight ofXCl sample) x 100%氯化物的重量分析法(通过沉淀氯化银来分析)介绍重量分析是通过一种化学反应把一种物质转化成另一种可溶解和称量的已 知化学合成物来决定这种物质的总量。在本实验中我们通过氯离子和阴离子生成氯化银沉淀来测定未知氯化物的 成分。过滤并称量氯化银。根据已知氯化
7、银反应化学计量比我们可以测出样品中 氯化物的量。Ag+ (aq) - Cl- (aq) - AgCl将称过的未知氯化物溶于水中，氯化物在水中将分离出G-和、广：XCL (s)- HzO (aq) - X+ (aq)-CL- (aq) - HzO (aqj力口入AgNOs提供縮，倔fCh加入辿C1立刻从溶液中析出。亘驭5被加 到直到厶弍沉淀不再析出为止，$最初的量被当成这个反应的极限药剂。被加 入的过量的書6没有止呂CL重要。然后我们过滤出AgCl沉淀并称量。通过氯化银沉淀的量我们可以测出的摩尔产生量。氯化银的摩尔量=氯化银的重量/氯化银的相对分子质量=氯化银的重量/143.32我们可以在未知物
8、中测定邕S的百分率：的摩尔量=3的摩尔量區在氯化物样品中的重量=口-的摩尔量X二T的原子量(35.4527)样品中33的百分率=（蛋1在氯化物样品中的重量/氯化物样品的重量x loo%ProcedureStep : Obtain unknown in a 250 nJ Beaker add 呂 of unknown cHoride XC1.Step 2 Add 乐诅ter to XC1= fill beaker to 1 DOnJ level by adding water； stir solution until XC1 is completeljr dissolved-Stip 3: Ad
9、d Con匚亡ntr呂tudNhrkadd 1 nJ ofconcentrated acid to XC1 solution.Step 4: Add IM A亦Ch： Obtain a 1 OOnJ graduated cylinder and fill with IM AgNO3: add AgNOs to XC1 sohjtioD in 5 to 25 ml increments. A precipitate of AgCl will form and gradually settle. Continue to add A呂NO 3 until no more precipitate fo
10、rms. T veri5r that the reaction is complete check the chemical properties of the beaker (by double-clicking on it) and confirm that all of the XC1 (in solution) has been consumed.Stcp 5: Filter anti av亡igh AgCH : Obtain a. 250nJ Erlenmeyer flask and add a. fitter； pour the contents of the beaker int
11、o the ilask. Remove the filter from the Erlenmeyer flask (by again selecting the filter menu or button) and savre the solid contents in a. watch glass. Weigh the sample and record the result. s*Note that in an actual lab the AgCl filtered precipitate ould need to be dried to remmr亡 excess water； how
12、ever in this simulation the filtered pi巳匚ipitate is free of water.步骤 ：第一步：获得未知物，在一个250ml烧杯中加入5g未知氯化物。第二步：向氯化物中加水，向烧杯中加入100ml水，直到氯化物完全溶 解。第三步：加入浓硝酸，向氯化物溶液中加入lml浓硝酸。第四步：加入lm呈型，拿一个有刻度的容器，向里面加入lmAgNCh，把A亦5加入氯化物溶液中以5到25ml的增加量。聞 沉淀将会逐渐形成。继续添加渤?直到没有沉淀生成。核实这个反应完成的方法是通过双击检查烧杯中的化学特性并且确认溶液中的氯化物已经完全反应。第五步：过滤和称量
13、海：拿一个250ml锥形瓶并放一个过滤器，把烧 杯中的东西倒入过滤器中。把过滤器从烧杯上移开（通过再次选择过滤器或 按钮）并且把产物放在玻璃器皿上。称样品的重量并记录实验结果。注意：在真实的实验室中，他C1沉淀需要干燥脱水，然而在这个模拟 实验中得到的沉淀是没有水的。Observatioiis:Initial unknown chlonde sample weight (g):Weight of AgCl precipitate:Approximate volume of AgNO3 solution added (ml):Moles of AgCl = (AgCl precipitate m
14、ass/143.32 ): Weight of Cl- in XC1 sample = (moles of AgCl)x(atomic weight ofCl- = 35.4527):% Cl- in sample = (weight of Cl- in XC1 sample / weight ofXCl sample) x 100% :What happened as excess AgNO3 solution was added to the XC1 solution ?观察：最初的未知氯化物重量； 氯化银沉淀的量；粗略估计硝酸银溶液的加入量；氯化银的摩尔量=氯化银沉淀的量/ 143.32 氯化物样品中氯离子的量=氯化银的摩尔质量X氯氯离子的原子量 （35.4527）样品中氯离子的百分率二（氯化物样品中氯离子的重量/氯化物的重 量）X100%当硝酸银溶液加入过量时发生了什么？Chemicals血屋睦relIEilrel匪匪匪一ChemLab - FilterAn amount of solid was found present in the filterof this piece of lab equipment!:Svnple Weight: 2.866 g
