Ch 19 Applications of Standard Electrode Potentials Flashcards
Are iron heme proteins in which a porphine ring is coordinated through nitrogen atoms to an iron atom
Cytochromes
When the concentration of certain species attain their equilibrium values and the current ceases, the system is said to have a potential of
The potential of the cell becomes zero
At equilibrium the electrode potentials for all half reactions in an oxidation reduction system are
Equal
The formula for the standard cell potential
E°cell = E°right - E°left
What equation should we use when dealing with the half cell potential
Nernst equation
A 25°C, the equilibrium constant of a reaction can be obtained via
log Keq = nE°cell/0.0592 = n(E°right-E°left)/0.0592
In calculating the electrode potential of a system from standard potential data we use
SHE / standard hydrogen electrode
Are substances that change color and being oxidized or reduced
General oxidation/ reduction (Redox) indicator
The color changes for general redox indicator depend only on the
Potential of the system
A class of organic compounds that form stable complexes with iron (II) and certain other ions
Orthophenanthrolines
Three orthopenanthroline molecules combined with each iron ion to yield a complex called
Ferroin
Is a widely used specific indicator in redox reaction involving iodine as an oxidant or iodide ion as a reductant
Starch
An indicator, starch form complexes with _______ to function as a true redox indicator
Triiodide ion
The best known specific indicator is _____, signals the endpoint and titration in which iodine is either produced or consumed.
Starch
The color end point of starch as an indicator in the presence of iodine
Dark blue complex or color
