归东理工大军 Analytical chemistry Chapter 6 Oxidation-reduction titration Learning objectives To master the fundamental principles and relevant calculations about oxidation-reduction equilibrium; To master the calculation of titration curve,the end point and the titration and the titration break; To know about the application of oxidatioton titration. 2022/11/19
Analytical chemistry Chapter 6 Oxidation-reduction titration Learning objectives ØTo master the fundamental principles and relevant calculations about oxidation-reduction equilibrium; ØTo master the calculation of titration curve, the end point and the titration and the titration break; ØTo know about the application of oxidation-reduction titration. 2022/11/19
©归东我子大 Analytical chemistry The word redox is frequently applied to oxidation- reduction reactions.A redox titration is based on an oxidation-reduction reaction between analyte and titrant. Even though many of the oxidizing agents can be used as titrants,few are primary standards.Most reducing agents react with oxygen and require protection from air to be used as titrant. 2022/11/19
Analytical chemistry The word redox is frequently applied to oxidationreduction reactions. A redox titration is based on an oxidation-reduction reaction between analyte and titrant. Even though many of the oxidizing agents can be used as titrants, few are primary standards. Most reducing agents react with oxygen and require protection from air to be used as titrant. 2022/11/19
归东理工大军 Analytical chemistry 6.1 Redox reaction 1.Conditional potentials A redox reaction often can be arranged as a cell,such as: Zn ZnSO (x mol/L)CusO(y mol/L)Cu At anode,Zn is oxidized Zn-2eU Zn2 At cathode,Cu2+is reduced Cu2 +2eU Cu 2022/11/19
Analytical chemistry 6.1 Redox reaction 1. Conditional potentials A redox reaction often can be arranged as a cell, such as: At anode, Zn is oxidized At cathode, Cu2+ is reduced 2022/11/19
G山东我子大写 Analytical chemistry The electromotive force of the cell can be obtained from the difference between the potentials of the two electrodes E=j.j(cuicu)-(ngn) The potentials of the electrodes is obtained by Nernst equation i=i+ RIIn ox nF a Red So the potentials of the electrodes is determined by the activities of the oxidized and reduced forms.At the unit activities,it is the standard potential. 2022/11/19
Analytical chemistry The electromotive force of the cell can be obtained from the difference between the potentials of the two electrodes The potentials of the electrodes is obtained by Nernst equation So the potentials of the electrodes is determined by the activities of the oxidized and reduced forms. At the unit activities, it is the standard potential. 2022/11/19
G山东子大图 Analytical chemistry In practice,however,some factors that affect the potential should be taken into account.For instance,consider the potential of the Fe3+/Fe2+couple in the presence of HCl. /-/0+0.0591g4e -j°+0.0591 g Se1 8e[Fe2+] In the HCI solution,ferric ion complex with H,O and Cl as follows 2022/11/19
Analytical chemistry In practice, however, some factors that affect the potential should be taken into account. For instance, consider the potential of the Fe3+/Fe2+ couple in the presence of HCl. In the HCl solution, ferric ion complex with H2O and Cl- as follows : 2022/11/19