When an oxide of manganese (A) is fused with KOH in the presence of an oxidising agent and dissolved in water, it gives a dark green solution of compound (B). Compound (B) disproportionates in neutral or acidic solution to give purple compound (C ) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds A to D and also explain the reactions involved.

When an oxide of manganese (A) is fused with KOH in the presence of an

1.	When an oxide of manganese (A) is fused with KOH in the presence of an oxidising agent and dissolved in water, it gives a dark green solution of compound (B). Compound (B) disproportionates in neutral or acidic solution to give purple compound (C ) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds A to D and also explain the reactions involved.
Answer» Solution :`A: MnO_(2) , B: K_(2)MnO_(4)` `C: KMnO_(4), D : KIO_(3)` `UNDERSET((A))(2MnO_(2)) + 4KOH + O_(2) rarr underset((B))(2K_(2)MnO_(4)) + 2H_(2)O` `3MnO_(4)^(2-) + 4H^(+) rarr underset((C ))(2MnO_(4)^(-)) + MnO_(2) + 2H_(2)O` `2MnO_(4)^(-) + H_(2)O + KI rarr 2MnO_(2) + 2OH^(-) + underset((D))(2KIO_(3))`