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The d & f Block Elements — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryThe d & f Block Elements3 Marks
Question
E° values of Mn, Ni and Zn are more negative than expected.
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Answer

Negative $\mathrm{E}^{\circ}$ values for $\mathrm{Mn}^{2+}$ and $\mathrm{Zn}^{2+}$ are related to stabilities of half-filled and fully filled configurations, respectively. But for $\mathrm{Ni}^{2+}, \mathrm{E}^{\circ}$ value is related to the highest negative enthalpy of hydration.

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