Ladder diagrams are useful tools for understanding redox equilibrium reactions, especially the effects of concentration changes on the electrochemical potential of the reaction. The vertical axis in the redox ladder diagrams represents the electrochemical potential, E. The area of predominance is demarcated using the Nernst equation.
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+ predominates at potentials more negative than +0.771 V. When the Fe3+/Fe2+ half-reaction is coupled with the Sn4+/Sn2+ reaction, the concentration of Fe3+ can be reduced by adding Sn2+ to excess. In this case, the potential of the resulting solution approaches +0.154 V down to +0.771 V, and Fe2+ and Sn4+ predominate.
To understand the interdependence between change in solution pH and electrochemical potential, consider the example of UO22+/U4+ half-reaction, whose electrochemical potential varies with the pH of the solution. As the pH of the solution decreases, the electrochemical potential increases, changing the dominant species from U4+ to UO22+.
来自章节 2:
Now Playing
Chemical Equilibria
443 Views
Chemical Equilibria
1.3K Views
Chemical Equilibria
1.4K Views
Chemical Equilibria
907 Views
Chemical Equilibria
1.4K Views
Chemical Equilibria
550 Views
Chemical Equilibria
764 Views
Chemical Equilibria
656 Views
Chemical Equilibria
559 Views
Chemical Equilibria
465 Views
Chemical Equilibria
333 Views
Chemical Equilibria
611 Views
Chemical Equilibria
959 Views
Chemical Equilibria
639 Views
Chemical Equilibria
470 Views
See More
版权所属 © 2025 MyJoVE 公司版权所有,本公司不涉及任何医疗业务和医疗服务。