when a pyrolusite ore MnO2 is fused with KOH in presence of air, a green coloured compound (A) is obtained which undergoes disproportionation reaction in acidic medium to give purple coloured compound (B).
(i) Write the formulae of the compound (A) & (B).
(ii) What happens when compound (B) is heated?
MnO2 +KOH + O2----> K2MnO4 (A)+ H2O
K2MnO4 + H+--> KMnO4 (B)
KMnO4 -- HEAT---> MnO2 + KOH+ H2O
K2MnO4 + H+--> KMnO4 (B)
KMnO4 -- HEAT---> MnO2 + KOH+ H2O