第六章：电化学(无机)教学提纲.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,物理化学,第六章 电化学,Electrochemistry,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,学习要求：,理解原电池与电解池的异同点；理解电导、电导率、摩尔电导率的定义及其应用。,掌握电解质的活度、离子平均活度和离子平均活度系数的定义及计算。,掌握离子迁移数的定义。掌握离子独立运动定律和德拜,休克尔极限定律。,重点掌握电池反应和电极反应的能斯特方程，会利用能斯特方程计算电池电动势和电极电势。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,第六章 电化学,6.1 电解质溶液的导电机理及法拉第定律,6.2 离子的迁移数,6.3 电导、电导率和摩尔电导率,6.4 电解质的平均离子活度因子及德拜休克尔极限公式,6.5 可逆电池及其电动势的测定,6.6 原电池热力学,6.7 电极电势和液体接界电势,6.8 电极的种类,6.9 原电池设计举例,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电化学研究对象,电能,化学能,电解,电池,电化学主要是研究,电能和化学能之间的相互转化及转化过程中有关规律,的科学。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,原电池：,电解池：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电化学的用途,电解 精炼和冶炼有色金属和稀有金属,电解法制备化工原料；,电镀法保护和美化金属；,还有氧化着色等。,电池 汽车、宇宙飞船、照明、通讯、,生化和医学等方面都要用不同类 型的化学电源。,电分析 药物的监测和分析,生物电化学 生物氧化还原、体内代谢研究,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,发电鞋,利用水的压力发电,利用土豆发电,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,发电地毯,德国人利用摩擦生电的原理发明了一种能发电的地毯，他将发电线圈随着地毯的花纹进行巧妙的编织。,当人踏在地毯上时即能发电，可作为冰箱、洗衣机及电视机等的能源，也可对蓄电池充电。,一位美国工程师也设计出一种发电地毯。将这种装置埋在大街、车站、舞厅等公共场所的地毯下，所发出的电可以用来照明和驱动电风扇。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,燃料电池,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,燃料电池,用燃料电池的汽车,标致,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,燃料电池,燃料电池的汽车生成的纯水,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,波音公司第一架氢能源飞机,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,Li 离子电池的工作原理,负极,正极,锂原子,石墨,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,路灯,交通灯,风扇凉帽,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,发电站,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,太阳能工厂(德国),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,北京太阳能综合利用示范楼,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,太阳能电池,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,两类导体,又称电子导体，如金属、石墨等。,1.第一类导体,第二类导体,又称离子导体，如电解质溶液、熔融电解质等。,第一类导体靠电子定向移动。第二类导体靠离子的电迁移，是阴阳离子共同作用的结果。,离子迁移数：某种离子传输的电量,I,B,与总电量,I,之比，称为该离子的迁移数。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,正极、负极,电势,低,的极称为,负,极，电子从负极流向正极。,负极：,电势,高,的极称为,正,极，电流从正极流向负极。,正极：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,阴极、阳极,发生,还原作用,的极称为,阴极,，在原电池中，阴极是正极；在电解池中，阴极是负极。,阴极：,(Cathode),发生,氧化作用,的极称为,阳极,，在原电池中，阳极是负极；在电解池中，阳极是正极。,阳极：,(Anode),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,原电池(galvanic cell),Cu,2+,+2e,-,Cu(S),发生还原作用，是,阴极,。电流由Cu极流向Zn极，Cu极电势高，是,正极,。,Cu电极,：,Zn(S)Zn,2+,+2e,-,发生氧化作用，是,阳极,。电子由Zn极流向Cu极，Zn极电势低，是,负极,。,Zn电极,：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电解池(electrolytic cell),与外电源正极相接，是,正极,。,发生氧化反应，是,阳极,。,Cu(S)Cu,2+,+2e,-,电极：,与外电源负极相接，是,负极,。,发生还原反应，是,阴极,。,Cu,2+,+2e,-,Cu(S),电极：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2.法拉第定律(,Faraday Law),通过电极的电量正比于电极反应的反应进度与电极反应电荷数的乘积,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,法拉第定律的文字表述,在电极界面上发生化学变化物质的质量,与通入的电量成正比。,通电于若干个电解池串联的线路中，当所取的基本粒子的荷电数相同时，,在各个电极上发生反应的物质，其物质的量相同,，析出物质的质量与其摩尔质量成正比。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,F,=,eL,=,1.6021917,10,-19,6.022169 10,23,=9.64868 10,4,Cmol,-1,96500 Cmol,-1,法拉第常数在数值上等于,1 mol,元电荷的电量,。,已知元电荷电量为,1.602210,-19,C,法拉第常数(,Faraday constant),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,1.离子迁移数的定义,阴离子,阳极,阳离子,阴极,6.2 电解质溶液电导,电迁移,离子在电场下的定向运动。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电解质溶液的导电任务是由正、负离子共同承担，向阴、阳两极迁移的正、负离子物质的量总和恰好等于通入溶液的总电量。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,离子迁移数,某离子,i,运载的电量与通入溶液的总电量之比。,如果溶液中只有一种电解质，则：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,因为,I=Q/t,，则有,t,i,与迁移速率,v,的关系,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2.离子迁移数的测定方法,希托夫法(,Hittorf method,),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,G,电导（,-1,or S）,电导率(,-1,m,-1,or S/m),6.2 电导、电导率和摩尔电导率,1.定义,（1）电导,（2）电导率,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,对于电解质溶液而言，,电导率,是电极面积各为,1m,2,、两电极相距,1m,时溶液的电导，其数值与电解质的种类、浓度及温度等因素有关。,电导率,单位立方体,面积=A,电导,G=,A/l,长度=,l,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,几种类型的电导池：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,Sm,2,mol,-1,（3）摩尔电导率,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电导的测定,电导测定的装置,电导测定实际上测定的是电阻，常用的,韦斯顿电桥,如图所示。,AB,为均匀的滑线电阻，为可变电阻，并联一个可变电容 以便调节与电导池实现阻抗平衡，,M,为放有待测溶液的电导池，电阻待测。,I,是频率在,1000Hz,左右的,高频交流电源,，,G,为耳机或阴极示波器。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电导的测定,测定时，接通电源，选择一定电阻的,R,2,，移动接触点,C,，直到检流计,G,显示为零，此时电桥平衡。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电导的测定,几种类型的电导池：,电导池电极通常用两个平行的铂片制成，为了防止极化，一般在铂片上镀上铂黑，增加电极面积，以降低电流密度。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,单位是,m,-1,因为两电极间距离,l,和镀有铂黑的电极面积,A,无法用实验测量，通常用已知电导率的,KCl,溶液注入电导池，测定电阻后得到,K,cell,。然后用这个电导池测未知溶液的电导率。,电导池常数（,cell constant,）,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电导率与浓度的关系,强电解质,溶液的电导率随着浓度的增加而升高。当浓度增加到一定程度后，解离度下降，离子运动速率降低，电导率也降低，如 和,KOH,溶液。,弱电解质,溶液电导率随浓度变化不显著，因浓度增加使其电离度下降，粒子数目变化不大，如醋酸。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电导率与浓度的关系,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,摩尔电导率与浓度的关系,由于溶液中导电物质的量已给定，都为,1mol,，所以，当,浓度降低,时，粒子之间相互作用减弱，正、负离子迁移速率加快，溶液的,摩尔电导率必定升高,。但不同的电解质，摩尔电导率随浓度降低而升高的程度也大不相同。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,强电解质的 与c的关系,是与电解质性质有关的常数。将直线外推至，得到无限稀释摩尔电导率,L,。,L,m,随着浓度下降，升高，通常当浓度降至 以下时，与 之间呈线性关系。德国科学家,Kohlrausch,总结的经验式为：,L,m,L,m,L,m,=,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,强电解质的,L,m,与c的关系,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,弱电解质的 与c的关系,随着浓度下降，也缓慢升高，但变化不大。当溶液很稀时，与 不呈线性关系，等稀到一定程度，迅速升高，（见 的 与 的关系曲线）。,弱电解质的 不能用外推法得到。,L,m,L,m,L,m,L,m,L,m,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,4.离子独立运动定律,（1）离子独立运动定律,在无限稀释溶液中，每种离子独立移动，不受其它离子影响，电解质的无限稀释摩尔电导率可认为是两种离子无限稀释摩尔电导率之和。,m,（KCl）,S,m,2,mol,-1,0.01499,m,（KNO,3,）,S,m,2,mol,-1,0.01450,m,（LiCl）,S,m,2,mol,-1,0.01150,m,（LiNO,3,）,S,m,2,mol,-1,0.01101,0.00349,0.00349,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,（2）弱电解质无限稀释摩尔电导率的求法,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,5.电导测定的应用,AB =A,+,+B,c,0 0,c,(1-,),c c,（1）计算弱电解质的解离度和解离常数,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,（2）计算难溶盐的溶解度,Ag Cl(s)Ag,+,+Cl,-,2）求,：难溶盐本身的电导率很低，这时水的电导率就不能忽略,1）在无限稀释溶液中,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,(3）电导滴定,在滴定过程中，离子浓度不断变化，电导率也不断变化，利用电导率变化的转折点，确定滴定终点。电导滴定的优点是,不用指示剂,，对,有色溶液和沉淀反应,都能得到较好的效果，并能自动纪录。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,(4）测定水的纯度,水的种类,电导率值/（S,m,-1,),普通自来水,1.0,10,-1,(1000,m,S,cm,-1,),蒸馏水,1.0,10,-3,(10,m,S,cm,-1,),重蒸水,1.0,10,-4,(1,m,S,cm,-1,),反复蒸馏的水,6.3,10,-6,药用去离子水,1.0,10,-4,检验用去离子水,1.0,10,-3,水的理论电导率（298K）,5.5,10,-6,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,6.4,溶液中电解质的活度和活度系数,1.离子活度和离子浓度,2.离子活度因子,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2.离子强度,(,ionic strength,),离子强度（,I,）,等于溶液中每种离子,B,的质量摩尔浓度,b,B,乘以该离子的价数的平方所得诸项之和的一半。,在稀溶液范围内,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,25时，计算0.01mol/kg的NaNO,3,和0.001mol/kg的Mg(NO,3,),2,的混合溶液的离子活度。,【解】,注意：离子强度是针对溶液中的所有电解质。,例 题,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,在稀溶液中，强电解质是完全电离的。,离子间的相互作用主要是静电引力。即电解质溶液偏差理想溶液主要由于离子间静电引力引起。,离子所形成的静电场是球形对称的（,离子氛,），每个离子可看成是点电荷。,假设,3.德拜-休克尔极限公式,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,离子氛,静电引力,（使离子周围出现异号离子,的几率大于同号离子）,热运动,（力图使离子均匀分散）,（1）离子氛,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,Debye-Huckel limiting Law,在一定条件下，A是常数，与溶剂密度、介电常数等有关。,298.15K,水溶液中,适用范围:,I,沉积,M,不活泼,沉积,溶解,M,n+,浓,M,M,n+,(aq)+ne,-,双电层,双电层间的电势差,实际上就是氧化还原电对的平衡电势,称之为,电极反应的电势,简称为,电极电势,(,E,本书用“,”表示.),电极电势,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电动势的值,E=,接触,+,-,+,扩散,+,+,接触,-,扩散,+,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,3.液体接界电势:扩散电势,E,j,2.接触电势,E,c,1,.电极电势差,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,4）盐桥只能降低液接电势，但不能完全消除，,1）盐桥中离子的,t,+,t,-,，使,E,j,0,。,2）常用饱和KCl盐桥，因为K,+,与Cl,-,的迁移数相近，当有Ag,+,时用KNO,3,或NH,4,NO,3,。,3）盐桥中盐的浓度要很高，常用饱和溶液,。,液接电势的消除盐桥（Salt bridge,）,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,标准电极电势,标准氢电极装置图,氢电极,电极反应,:,H,2,(g)-2e,-,H,+,(aq),氢电极,半电池,:,Pt|H,2,(100kPa)|H,+,(1molL,-1,),规定:,(,H,+,/,H,2,)=,H,+,/,H,2,=0.000V.,标准氢电极,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,标准氢电极,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,标准电极电势,2、标准电极电势,标准氢电极与其它各种标准状态下的电极组成原电池，,标准氢电极定在左边,，用实验方法测得,这个原电池,的电动势数值，就是该电极的标准电极电势。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,(-)Zn|Zn,2+,(,1molL,-1,)|,H,+,(1molL,-1,)|H,2,(,100k,Pa),Pt(+),298K时测得标准电动势,E,=,0.763V.,据,E,=,(+),-,(-),=,(H,+,/,H,2,),-,(,Zn,2+,/,Zn,),(H,+,/,H,2,),=0.000V,(,Zn,2+,/,Zn,)=-0.763V,例如,Zn,2+,/,Zn电极反应电势的测定:,标准电极电势,(Ox/Red),:,298K,电极反应中各组分均处于标准态时所测得的电极电势。,标准电极电势与标准电极电势表:,标准电极电势,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,标准电极电势表,本课程标准电极电势表按照IUPAC的系统，氢以上为负，氢以下为正。,标准电极电势的符号是正或负，不因电极反应的写法而改变,。,标准电极电势表,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,标准电极电势表都分为两种介质,(附录),：酸性、碱性溶液。什么时候查酸表、或碱表？有几条规律可循：,（1）H,+,无论在反应物或产物中出现皆查酸表：,（2）OH,-,无论在反应物或产物中出现皆查碱表：,（3）没有H,+,或OH,-,出现时，可以从存在状态来考虑。如Fe,3+,+e,-,Fe,2+,，Fe,3+,只能在酸性溶液中存在，故在酸表中查此电对的电势。若介质没有参与电极反应的电势也列在酸表中，如Cl,2,+2e,-,2Cl,-,等。,标准电极电势表,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2.标准电极电势表的应用,（1）判断氧化剂和还原剂的强弱,标准电极电势数值越小，其还原型的还原性越强，氧化型的氧化性越弱，反之亦然。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,在标准状态下将反应物中还原型和它的产物的电对作负极：(-)Zn,2+,+2e,-,Zn,将反应物中氧化型和它的产物的电对作正极,:,(+)Cu,2+,+2e,-,Cu,查出标准电势，求出电池电动势：,E,=,+,-,-,=0.337V-(-0.7628V)=1.10V,若,E,0,则反应自发正向进行，以符号“”表示；若,E,0,，反应向右自发进行。所以三氯化铁溶液可以氧化铜板。,（2）判断反应的方向,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,判断氧化还原的方向,已知：,试判断下述反应向哪方进行？,排成电池：设活度均为1,正向进行,。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电极电势与浓度关系-能斯特方程,对于任一反应：,aA+bB=dD+eE,这个方程叫能斯特方程,当,T,=298K时，能斯特方程为：,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,电极电势与浓度关系-能斯特方程,对于任一反应：,aA+bB=dD+eE,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2MnO,4,-,+16H,+,+10Cl,-,2Mn,2+,+8H,2,O+5Cl,2,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,MnO,4,-,+8H,+,+5e,-,Mn,2+,+4H,2,O,2Cl,-,-2e,-,Cl,2,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,Cu,2+,/mol.L,-1,Zn,2,+,/mol.L,-1,E/V,2,0.01,1.168,1.5,0.51,1.141,1.005,1.005,1.1,0.51,1.5,1.085,0.01,2,1.032,0.001,2.009,1.002