Write the balanced equations for the reactions when
(i). Potassium permanganate interacts with manganese dioxide in the presence of potassium hydroxide.
(ii). Potassium ferrocyanide is heated with concentrated sulphuric acid.

Explanation

(i). When potassium permanganate interacts with manganese dioxide in the presence of potassium hydroxide, potassium manganate is formed
`2KMnO_4+4KOH+MnO_2to3K_2MnO_4+2H_2O`
(ii). When potassium ferrocyanide is heated with concentrated sulphuric acid, CO is evolved.
`K_4Fe(CN)_6+6H_2SO_4+6H_2Oto2K_2SO_4+FeSO_4+3(NH_4)_2SO_4+6COuarr`
When potassium ferroxyanide is heated with dilute sulphuric acid, HCN is evolved, which is poisonous gas.