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+.
Del capítulo 2:
Now Playing
Chemical Equilibria
418 Vistas
Chemical Equilibria
1.2K Vistas
Chemical Equilibria
1.3K Vistas
Chemical Equilibria
856 Vistas
Chemical Equilibria
1.3K Vistas
Chemical Equilibria
515 Vistas
Chemical Equilibria
722 Vistas
Chemical Equilibria
621 Vistas
Chemical Equilibria
531 Vistas
Chemical Equilibria
437 Vistas
Chemical Equilibria
310 Vistas
Chemical Equilibria
584 Vistas
Chemical Equilibria
924 Vistas
Chemical Equilibria
603 Vistas
Chemical Equilibria
425 Vistas
See More
ACERCA DE JoVE
Copyright © 2025 MyJoVE Corporation. Todos los derechos reservados