Name: manganese(IV) oxide; manganese dioxide
* IUPAC
CAS Number: 1313-13-9
Chemical Formula: MnO₂
Molar Mass: 86.936849 g
Mass Percent: Mn 63.193 %; O 36.806 % 

• inorganic

• "...MnO₂ is used in dry cells (flashlight "batteries") and as an oxidant in the chemical industry." 1

• "The mineral is the source of manganese and all its comp[oun]ds; largely used in manuf[acturing] manganese steel; oxidizer; in alkaline batteries (dry cells); for making amethyst glass, decolorizing glass; painting on porcelain, faience and majolica. The ppt [precipitate] is used in electrotechnics, pigments, browning gun barrels, drier for paints and varnishes, printing and dyeing textiles. " 2

4 Al (s) + 3 MnO2 (s) → 2 Al2O3 (s alpha-corundum) + 3 Mn (s) 6
4 HCl (aq) + 1 MnO2 (s) → 2 H2O (ℓ) + MnCl2 (aq) + 1 Cl2 (g) 7
2 KMnO4 (aq) + 3 KCN (aq) + H2O (ℓ) → 2 MnO2 (s) + 2 KOH (aq) + 3 KOCN (aq) 

Wikipedia

(1) - Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 8.
(2) - The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 13th ed.; Budavari, S.; O'Neil, M.J.; Smith, A.; Heckelman, P. E.; Kinneary, J. F., Eds.; Merck & Co.: Whitehouse Station, NJ, 2001; entry 5753.
(3) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(4) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(6) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 206.
(7) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 117.