Question

Based on data arrange fe2+,. mn2+ and cr2+ in the increasing order of stablity of +2 oxidation state .

Answer 1

cr +2> fe+2>mn+2...

is the correct answer

Answer 2

Explanation:

Atomic number of manganese is 25 and its electronic configuration is $[Ar]4s^{2}3d^{5}$.

Therefore, for $Mn^{2+}$ electronic configuration is $[Ar]4s^{0}3d^{5}$. Since, it has half filled d-orbital so it has highest stability.

Atomic number of chromium is 24 and its electronic configuration is $[Ar]4s^{1}3d^{5}$.

Therefore, for $Cr^{2+}$ electronic configuration is $[Ar]4s^{0}3d^{4}$.

On the other hand, atomic number of iron is 26 and its electronic configuration is $[Ar]4s^{2}3d^{6}$.

Therefore, for $Fe^{2+}$ electronic configuration is $[Ar]4s^{0}3d^{6}$. Since, exchange energy of $Fe^{2+}$ is more than the exchange energy of $Cr^{2+}$.

Hence, $Fe^{2+}$ is more stable than $Cr^{2+}$.

Thus, we can conclude that the increasing order of stablity of +2 oxidation state is as follows.

              $Mn^{2+}$ > $Fe^{2+}$ > $Cr^{2+}$