Class 12th Chemistry 2017 Set2 Delhi Board Paper Solution
Account for the following:
E° value for the Mn3 + / Mn2 + couple is highly positive (+1.57V) as compare to Cr3 + / Cr2 + .
The high value of E° value for Mn3 + / Mn2 + shows that Mn2 + is much more stable than Mn3 +. This is due to the fact that Mn2 + has a 3d5 configuration which is half filled and hence is very stable whereas, Cr2+ and 3d4 configuration. It can lose e- to form Cr3+ which has stable 3d3 configuration (half filled t2g). Hence, less E° Cr3 + / Cr2 +
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