A violet compound of manganese (A) decomposes on heating to liberate oxygen and componds (B) and (C ) of manganese are formed. Compound (C ) reacts with KOH in the presence of potassium nitrate to give compound (B). On heating compound (C ) with conc. `H_(2)SO_(4)` and NaCl, chlorine gas is liberated and a compound (D) of manganese along with other products is formed. Identify compounds (A)to (D) and also explain the reactions involved.

Explanation

`A rArr KMnO_(4), B rArr K_(2)MnO_(4), C rArr MnO_(2), D rArr MnCl_(2)`
Reactions :
(i) `2KMnO_(4)(A)overset(Delta)rarr K_(2)MnO_(4)(B)+MnO_(2)(C )+O_(2)`
(ii) `MnO_(2)+2KOH+KNO_(3)rarr K_(2)MnO_(4)+KNO_(2)+H_(2)O`
(iii) `MnO_(2)+4NaCl + 4H_(2)SO_(4)rarr underset((D))(MnCl_(2))+4NaHSO_(4)+Cl_(2)+2H_(2)O`