Black powder, soluble in acid, Insoluble in water and nitric acid, nonpoisonous Chemical Formula: MnO2 Molecular Weight: 86.94 Density: 5. ... 026 g/cm3 Appearance: Black powder, soluble in acid, Insoluble in water and nitric acid, nonpoisonous Typical Analysis: ItemAlkaline Battery GradeZinc-Carbon GradeMnO291 ...