8.17 For M^{2+}/Mand M^{3+}/M^{2+} systems the E^{\ominus } values for some metals are as follows:

         \\Cr^{2+}/Cr\; \; \; \; \; \; \; \; \; \; \; \; -0.9V\\Mn^{2+}/Mn\; \; \; \; \; \; \; \;\; \; -1.2V\\Fe^{2+}/Fe\; \; \; \; \; \; \; \; \; \; \; \; \; -0.4V 

         \\Cr^{3}/Cr^{2+}\; \; \; \; \; \; \; \; \; \; \; \; -0.4V\\Mn^{3+}/Mn^{2+}\; \; \; \; \; \; \; \; +1.5V\\Fe^{3+}/Fe^{2+}\; \; \; \; \; \; \; \; \; \; \; +0.8V        

 Use this data to comment upon:

(ii) the ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.

 

Answers (1)
A Ankit

From the values of E^{o}, the order of oxidation of the given metal to the divalent cation is-

Mn>Cr>Fe

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