Corrosion of Steel Lab Report
The reaction occurring at this electrode is a catholic reaction and as such the bubbles can be deduced to be H2O gas from the reactants involved. EH+ + e- ?+ H2O(gas) No disconsolation of the Indicator means that no corrosion was occurring at this electrode. Electrodes 2 through till 5 showed no visible reaction. From inspection of a Parabola diagram It can be seen that for a pH of 2, Fee Is In the catholic Immunity region where no oxidation occurs, which Is why no reaction Is observed. Electrode 6 was seen to turn a distinct blue color due to the presence of Fee+ Ions.
This Is because the potential Involved In this oxidation reaction Is In the active region. Fee -9 Fee+ e- The potential at electrode 6 is not high enough to form a protective Crack layer, as the Cry does not have sufficient energy to oxides to Cry(all), therefore it corrodes. There was no visible reaction observed between electrodes 7 through till 22. This is because the potentials involved in these reactions are in the passive region. The Cry in the electrodes creates a protective layer of Crack which slows down the corrosion of the electrodes to the extent that it is unnoticeable to the naked eye.
A pink acculturation was observed at electrodes 23 and 24, which Indicates the presence of tons. Fee- Fee+ + e- This Is because at a certain potential the Cry(all) turns Into Cry(FL). This In turn breaks down the protective barrier layer, and exposes Fee+ Ions on the electrode underneath which make the pink color. We don’t see this pink color at any other points because in order for the Fee in the electrodes to noise energy needs to be absorbed before the reaction may continue, and this is supplied by the higher potential of the more anodic electrodes of higher numbers.