Electrochemical Cells
Out of platinum, iron, carbon and silver which would be the LEAST suitable as an electrode in a standard Fe3+/Fe2+ half cell, and why?
Pt usually is the metal of choice for making measurements of this type, because of its inertness AND because of reproducibility in measurements. Which metal is the most likely to "mess up" the concentrations of Fe(III)/Fe(II)?
To determine which metal would be the least suitable as an electrode in a standard Fe3+/Fe2+ half cell, we need to consider the properties of the metals and their potential to interfere with the Fe(III)/Fe(II) concentrations.
In this case, carbon would be the least suitable metal as an electrode in a standard Fe3+/Fe2+ half cell. The main reason is that carbon is reactive and can easily participate in various chemical reactions. Consequently, it can react with Fe(III) or Fe(II) species present in the half cell, leading to unintended side reactions. These side reactions can modify the concentrations of Fe(III)/Fe(II) ions and introduce errors in the electrochemical measurements.
On the other hand, platinum (Pt), iron (Fe), and silver (Ag) are relatively inert metals, which means they are less likely to react with the Fe(III)/Fe(II) species. Among these three metals, platinum is commonly chosen as the electrode material because it is highly inert, stable, and resistant to corrosion. Its inertness ensures that it does not undergo any significant chemical reactions that could interfere with the Fe(III)/Fe(II) concentrations, enhancing the reproducibility of the measurements.
To summarize, carbon would be the least suitable metal electrode in a standard Fe3+/Fe2+ half cell due to its reactivity, while platinum would be the most suitable metal due to its inertness and reproducibility in measurements.