Pyrolusite on heating with KOH in presence of air gives a dark green compound (A). The solution of (A) on treatment with sulphuric acid gives a purple colour compound (B). Compound (B) with concentrated Hâ‚‚SOâ‚„ gives (C) which can decompose to (D) and Oâ‚‚. What is the number of unpaired electrons in the cation of (D)?
