Fusion of `MnO_2` with KOH in the presence of `O_2` produces a salt W. Alkaline solution of W upon electrolytic oxidation yields another salt X. The manganese containing ions present in W and X, respectively, are Y and Z. Correct statement(s) is (are)

Options

A. In aqueous acidic solution, Y undergoes disproportionation reaction to give Z and `MnO_2.`
B. Both Y and Z are colored and have tetrahedral shape.
C. Y is diamagnetic in nature while Z is paramagnetic.
D. In both Y and Z, `pi` -bonding occurs between p-orbitals of oxygen and d-orbitals of manganese.

Answer

A, B, D

Explanation

The reactions involved are as follows:
`MnO_(2)+2KOH+O_(2) to underset(W)(K_(2)MnO_(4))+2H_(2)O`
`2K_(2)MnO_(4)(aq)+2H_(2)O(l) to underset(X)(2KMnO_(4))(aq) +2KOH(aq)+H_(2)(g)`
Now, given that `Y= [MnO_4]^(2-) and Z =[MnO_4]^(-)`.
On electrolysis, `[MnO_4]^(2-) underset("oxidation")overset("Electrochemical")to [MnO_(4)]^(-)+e^(-)` In acidic solution, `[MnO_4]^(2-)` undergoes disproportionation as shown:
`3[MnO_(4)]^(2-)+4H^(+) overset(H+)to underset((Z))(2[MnO_(4)]^(-))+MnO_(2)+2H_(2)O`