Chemistry - Complete d-block Question with Solution | TestHub

Statement (I) is true: ${\mathrm{MnO}}_2$ reacts with KOH and an oxidizing agent (like ${\mathrm{KNO}}_3$ or air) to form dark green ${\mathrm{K}}_2{\mathrm{MnO}}_4$ (potassium manganate).

$$2{\mathrm{MnO}}_2+4\mathrm{KOH}+{\mathrm{O}}_2⟶2{\mathrm{K}}_2{\mathrm{MnO}}_4+2{\mathrm{H}}_2\mathrm{O}$$

Statement (II) is true: Manganate ion (${\mathrm{MnO}}_4^{2-}$) undergoes electrolytic oxidation in alkaline medium to form permanganate ion (${\mathrm{MnO}}_4^{-}$).

$${\mathrm{MnO}}_4^{2-}⟶{\mathrm{MnO}}_4^{-}+{\mathrm{e}}^{-}$$

Both statements are correct.