化学原理期末考试总结.ppt

1,2011级223人参加本次期末考试,卷面成绩如下：,化学原理期末考试总结,90100分37人,8089分59人,7079分53人,6069分33人,60分以下41人;,最高分99.5分,他(她)们是：,路越(2011级1班),杜凯敏(2011级5班),最低分7分.,其中,2,2011级3班90分以上8人,平均74.50分;,2011级2班90分以上12人,平均79.62分;,2011级1班90分以上8人,平均74.89分;,2011级4班90分以上3人,平均67.23分;,2011级5班90分以上6人,平均69.95分.,3,Pt,能否,溶解,HNO3,在,中？,+,NO3-,H3O+,+,+,NO,+,H2O,Pt,Pt4+,+,4NO3-,16H3O+,+,3Pt,+,18Cl-,3PtCl62-,+,4NO,+,24H2O,Questions,4,已知,下列,物质:,MnO4-,Cr2O72-,H2O2,Cl2,Fe3+,I2etc.,PbSO4,Fe2+,Mn2+,Sn2+,Ti3+,S2-,I-,Znetc,氧化性,强弱:,MnO4-,Cl2,H2O2,Cr2O72-,Fe3+,I2,还原性,强弱:,Zn,S2-,Ti3+,Sn2+,I-,Fe2+,Mn2+,Why?,PbSO4,PbO2,PbO2,5,Chapter8,氧化,还原,反应,及,氧化,还原,平衡,Oxidation,-,Reduction,Reactions,(2),原子,守恒;,(3),电荷,守恒;,(4),反应,介质,条件,要,合理.,酸性条件下只出现H+，碱性条件下只出现OH-.一个完整的氧化还原反应方程式不能同时出现H+和OH-,19,黄色,As2S3,溶解,在,HNO3,中,As2S3,+,HNO3,H3AsO4,+,H2SO4,+,NO,(5-3)2,+,(6+2)2,=,28,(2-5),=,-3,3,28,3As2S3,+,28HNO3,+,4H2O,=,6H3AsO4,+,9H2SO4,+,28NO,20,2-2,The,ion,-,electron,method,离子,电子,法,1.,先将,反应物,和,产物,以,离子式,列出:,As2S3,+,ClO3-,H3AsO4,+,SO42-,+,Cl-,2.,分别,写出,氧化剂,被还原,还原剂,被氧化,的,半反应,并且,配平;,ClO3-,+,6e-,+,6H+,Cl-,+,3H2O,As2S3,-,28e-,+,20H2O,2H3AsO4,+,3SO42-,+,34H+,21,3.,根据,氧化,还原,反应,得失,电子,相等,将,两个,半反应,乘以,相应,系数,合并,成,一个,配平,的,离子,方程式:,14,+,3,3As2S3,+,14ClO3-,+,18H2O,=,6H3AsO4,+,9SO42-,+,14Cl-,+,18H+,22,8-3,电极,电势,与,氧化,还原,平衡,Electrode,Potential,半电池,两相,界面,用,分开,同相,不同,物种,用,“,”,溶液、,气体,要,注明,cB,pB;,纯,液体、,固体,和,气体,写在,惰性,电极,一边,用,“,”,or,or,“-”,分开.,24,2MnO4-,+,6H+,+,5H2O2,=,2Mn2+,+,5O2,+,8H2O,Such,as,Cell,Reaction,(-),Pt,O2(p),H2O2(c1),H+(c2),MnO4-(c3),Mn2+(c4),H+(c5),Pt,(+),2Au(CN)2-,+,Zn,=,Zn(CN)42-,+,2Au,(-),Zn,Zn(CN)42-,CN-,Au,(+),Au(CN)2-,CN-,25,5S2O82-,+,8H2O,+,2Mn2+,=,2MnO4-,+,10SO42-,+,16H+,(-),Pt,Mn2+(c1),MnO4-(c2),H+(c3),SO42-(c4),S2O82-(c5),Pt,(+),Lead,-Storage,铅蓄,电池,Exoelectrical,Reaction,放电,反应,Battery,26,Lead,-Storage,铅蓄,电池,Battery,(-),Pb,H2SO4(c),-,PbSO4,PbO2,-,PbSO4,(+),Cell,Reaction:,Electrode,Reaction:,PbO2,+,Pb,+,2SO42-,=,2PbSO4,+,2H2O,+,4H+,27,Symbol,The,of,Primary,Cell:,(-),Zn,Zn2+(c1),Cl-(c2),(+),Hg,-,Hg2Cl2,Cell,Reaction:,Electrode,Reaction:,28,2.,The,Type,of,Electrode,电极,的,类型,(1),Metal,-,Metal,ion,Electrode,Cu(s),Cu2+(c),(2),Gas,Ion,Electrode,Pt,29,(3),Metal,-,Indissolvable,Salt,Electrode,金属,与其,难溶,盐,电极,Calomel,Electrode,甘汞,电极,Hg,Cl-(c),-,Hg2Cl2,Electrode,Reaction,Hg2Cl2,+,2e-,2Hg,+,2Cl-,(4),Ion,-,Ion,Electrode,Pt,Mn2+(c1),MnO4-(c2),H+(c3),30,用高阻抗的晶体管伏特计(电位差计）可直接测量出E,3-2,电极,电势,Electrode,Potential,一、,Electromotive,Force,EMF,电动势,电池,正、,负,电极,之间,的,电势,差,31,二、,Electrode,Potential,1.,Formation,of,Electrode,Potential,Electric,Double,Layer,双,电层,模型,我们知道,金属晶体是靠金属键结合的,是靠金属的阳离子和自由电子之间的吸引力结合的.当把金属放入他的盐溶液中,会有两种倾向存在：,一方面金属表面的阳离子会与极性很强的H2O分子发生溶剂化作用,以水合离子的形式进入溶液中,把电子留在金属的表面上,这是金属溶解的过程,越活泼,盐溶液浓度越稀,此倾向越大；,另一方面,溶液的水合阳离子又会从金属表面获得电子,沉积在金属表面上,这是金属的沉积过程.金属越不活泼,盐溶液的浓度越大,这种倾向越大.,表面,电势:,电子,逃逸,金属,表面.,相间,电势:,32,金属,和其,盐溶液,间的,电势。,活泼,金属,不活泼,金属,电极,电势,-,由金属,表面,电势,和金属,与溶液,界面,处的,相间,电势,所组成。,33,2.,影响,电极,电势,大小,的,因素,The,Factors,That,Affect,Electrode,Potentials,of,Metals,(1),金属,种类;,(2),溶液,中,金属,离子,浓度;,Ion,Concentration,(3),Temperature,(4),Ambient,Condition,介质,条件,Metal,Types,Obvious:,绝对,值,不能,得到！,34,3-3,Standard,Electrode,Potential,标准,电极,电势,一、,Standard,Hydrogen,Electrode,and,Calomel,Electrode,氢,电极,标准,和,甘汞,电极,Pt,H2(g,p),H+(c),Regulation:,35,36,Calomel,Electrode,甘汞,电极,Hg,Cl-(c),-,Hg2Cl2,Electrode,Reaction,Hg2Cl2,+,2e-,2Hg,+,2Cl-,Standard,Calomel,Electrode,=,Saturation,Calomel,Electrode,=,=,=,37,二、,Standard,Electrode,Potential,of,Redox,Couple,电对,的,标准,电极,电势,1.,Standard,State,of,Ox.,-,Red.,Reactions,组成,电极,反应,离子,浓度,为,气体,组分,分压,液体,或,固体,纯,物质.,2.,Obtaining,for,Standard,Hydrogen,Electrode,is,38,Pole,Positive,氢,电极,标准,为,正极:,Ag,+,2H+,+,2I-,=,2AgI,+,H2,(-),Pt(+),Ag,-,AgI,I-,H2(p),H+(c),=,-,=,0.149V,=,-0.149V,Standard,Hydrogen,Electrode,is,Pole:,Negative,39,2Ag+,+,H2,=,2Ag,+,2H+,=,-,=,0.7996V,=,+0.7996V,Standard,Calomel,Electrode,is,Pole:,Negative,2ClO3-,+,10Hg,+,10Cl-,=,5Hg2Cl2,+,2H2O,+,12H+,+,Cl2,40,=,-,=,1.212V,=,+0.7996V,三、,Table,of,Standard,Electrode,Potential,1.,电极,电势,表中,均,对应,电极,反应,通式:,Ox,+,ne-,Red,H3O+,只,出现,Ox,一端,OH-,只,出现,Red,一端,至今,无一,例外.,41,2.,各,标准,电极,电位,依,代数值,递增,顺序,排列,H2,以上,为负,说明,电对,中,作为,还原型,物质,其,还原性,均比,H2,强;,H+,以下,为正,说明,电对,中,作为,氧化型,物质,其,氧化性,均比,H+,强.,越大,对应,氧化型,物质,氧化,能力,越强,对应,还原型,物质,还原,能力,越弱.,3.,是,强度,性质,与,得失,电子,多少,无关,即,与,电极,反应,书写,无关.,42,Cr2O72-,+,6e-,+,14H+,2Cr3+,+,7H2O,1/2Cr2O72-,+,3e-,+,7H+,Cr3+,+,7/2H2O,2Cr3+,+,7H2O,-,6e-,Cr2O72-,+,14H+,=,+1.330V,=,+1.330V,=,+1.330V,CrO42-,+,3e-,+,4H2O,Cr(OH)4-,+,4OH-,43,=,-0.130V,4.,查表,要,注意,溶液,pH,pH,=0,查,酸表;,pH,=14,查,碱表.,5.,是,热力学,数据,与,反应,速率,无关,不能,保证,动力学,性质,与,热力学,性质,不,发生,矛盾.,Such,as,=,-2.88V,1,0,107,53,=,-540.33,0,0,=,-,=,1.78,-,1.224,0,58,Questions,8-3,请,解释,把,H2O2,加到,IO3-,和,淀粉,的,酸性,溶液,会,看到,溶液,颜色,在,无色,和,深,蓝色,之间,作,周期,