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
  • 10
sorry sorry first reaction is  crt ..
the remaining crt reactions are:
2. K2MnO4 + H+ ---> KMnO4 (B)+ MnO2 + H2O + K+
3. KMnO4  ----- HEAT--->  K2MnO4 + MnO2 + O2
  • 18
thanx a lot
  • 9
Hi ...

  • -2
A = K2MnO4 / MnO4 ^2- , B= KMnO4 / MnO4 -- , C= IO3 - or KIO3 , D= I2
  • -1
What are you looking for?