Cadmium sulfide | CdS | CID 14783 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety ... covalent and write the appropriate formula for it. 11) dinitrogen trioxide N2O3. 12) nitrogen N2. 13) methane CH4. 14) lithium acetate LiC2H3O2. 15) phosphorus trifluoride PF3. 16) vanadium (V) oxide V2O5. 17) aluminum hydroxide Al(OH)3. 18) zinc sulfide ZnS. 19) silicon tetrafluoride SiF4. 20) silver phosphate Ag3PO4 Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. Elemental zinc reacts with strong bases forming hydrogen: Zn (s) + 2 OH − (aq) Zn(OH) 2 (s) + H 2 (g) Zn 2+ is precipitated by hydroxide ions as Zn(OH) 2 (white amorphous precipitate)  Zn 2+ (aq) + 2 OH − (aq) Zn(OH) 2 (s) By acid excess hydroxide, the precipitate is dissolved  Zn(OH) 2 (s) + 2 H + (aq) Zn 2+ (aq) + 2 H 2 O (l) Zn(OH) 2 (s) + 2 OH − (aq) [Zn(OH) 4] 2− (aq) Naming and Formulas for Ionic Compounds Ionic compounds are formed between oppositely charged ions usually consisting of a metal and one or more non-metals. An ion can be a single charged atom or a small group of atoms (molecule) with a charge.