Manganese dioxide will also react with sulfur dioxide to form manganese ii sulfate. Manganese iv oxide is the inorganic compound with the formula mno 2 this blackish or brown solid occurs naturally as the mineral pyrolusite which is the main ore of manganese and a component of manganese nodules the principal use for mno 2 is for dry cell batteries such as the alkaline battery and the zinc carbon battery. It is black and powdery.