Lead Oxides

Lead Oxides 

the chemical compounds of lead and oxygen: Pb₂O, PbO, PbO₂, Pb₃O₄, and Pb₂O₃. Lead oxide (PbO), peroxide (PbO₂), and red oxide, also called minium (Pb₃O₄), are of commercial value. The oxide PbO has the two crystal forms yellow red tetragonal α (massicot) and yellow orthorhombic β (litharge), with a transition point of 587°C. Both forms are poorly soluble in water (0.11 and 0.05 g per liter at 25°C) and have a melting point of 836°C. PbO is amphoteric, with predominantly basic properties. It is obtained through the oxidation of melted Pb with atmospheric oxygen, as well as through the thermal dissociation of lead hydroxide, carbonate, or nitrate. When heated in air (up to 400°–500°C), PbO converts to Pb₃O₄, an oxide with red tetragonal crystals. PbO₂, which has brown tetragonal crystals, is obtained upon interaction of red oxide and nitric acid. Lead peroxide is a strong oxidizing agent; when triturated with powdery sulfur or red phosphorus, it ignites even at room temperature.

PbO is used in the manufacture of lead glass and glazes; PbO₂ serves as an oxidizing agent in the chemical industry and in the manufacture of lead batteries; and Pb₃O₄ is used in the preparation of paints that protect metals from corrosion.