Adding PbO to industrial ceramics (as well as glass) makes the materials more magnetically and electrically inert (by raising their Curie temperature) and it is often used for this purpose. Depending on the glass, the benefit of using PbO in glass can be one or more of increasing the refractive index of the glass, decreasing the viscosity of the glass, increasing the electrical resistivity of the glass, and increasing the ability of the glass to absorb X-rays. The kind of lead in lead glass is normally PbO, and PbO is used extensively in making glass. With strong bases, PbO dissolves to form plumbite (also called plumbate(II)) salts: PbO + H 2O + OH − Via the intermediacy of oxo clusters such as [Pb PbO is amphoteric, which means that it reacts with both acids and with bases. PbO (red) → PbO (yellow) Δ H = 1.6 kJ/mol The red and yellow forms of this material are related by a small change in enthalpy: Metallic lead is obtained by reducing PbO with carbon monoxide at around 1,200 ☌ (2,200 ☏): PbO + CO → Pb + CO 2 The tetragonal and orthorhombic forms of PbO occur naturally as rare minerals. The tetragonal form is usually red or orange color, while the orthorhombic is usually yellow or orange, but the color is not a very reliable indicator of the structure. The PbO can be changed from massicot to litharge or vice versa by controlled heating and cooling. When PbO occurs in tetragonal lattice structure it is called litharge and when the PbO has orthorhombic lattice structure it is called massicot. The pyramidal nature indicates the presence of a stereochemically active lone pair of electrons. In the tetragonal form the four lead–oxygen bonds have the same length, but in the orthorhombic two are shorter and two longer. : 245 Structure Īs determined by X-ray crystallography, both polymorphs, tetragonal and orthorhombic feature a pyramidal four-coordinate lead center. Just like in Barton pot method, the supply of air and separators may also be used. The oxidation is achieved by collisions of the balls. The overall reaction is:Ģ Pb + O 2 450 ☌ (842 ☏) →2PbO Ball mill method The lead balls are oxidized in a cooled rotating drum. : 245 Oxides produced by this method are mostly a mixture of α-PbO and β-PbO. cyclonic separators) for further processing. The refined molten lead droplets are oxidized in a vessel under a forced air flow which carries them out to the separation system (e.g. There are two principal methods to make lead monoxide both of which resemble combustion of the lead at high temperature: Barton pot method. At a temperature of around 1,000 ☌ (1,800 ☏) the sulfide is converted to the oxide: 2 PbS + 3 O The usual lead ore is galena ( lead(II) sulfide). PbO is produced on a large scale as an intermediate product in refining raw lead ores into metallic lead. Thermal decomposition of lead(II) nitrate or lead(II) carbonate also results in the formation of PbO: At this temperature it is also the end product of decomposition of other oxides of lead in air: PbO 2 → 293 ° C Pb 12 O 19 → 351 ° C Pb 12 O 17 → 375 ° C Pb 3 O 4 → 605 ° C PbO PbO may be prepared by heating lead metal in air at approximately 600 ☌ (1,100 ☏). Yellow orthorhombic (β-PbO), which is obtained temperatures higher than 486 ☌ (907 ☏).Red tetragonal (α-PbO), obtained at lower temperatures than the β-PbO.Modern applications for PbO are mostly in lead-based industrial glass and industrial ceramics, including computer components. PbO occurs in two polymorphs: litharge having a tetragonal crystal structure, and massicot having an orthorhombic crystal structure. Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula Pb O.
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