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2 → 2 PbO + 4 NO 2 + O 2 PbCO 3 → PbO + CO 2. PbO is produced on a large scale as an intermediate product in refining raw lead ores into metallic lead. The usual lead ore is galena (lead(II) sulfide). At a temperature of around 1,000 °C (1,800 °F) in air, the sulfide converted to the oxide: [4] 2 PbS + 2 O 2 → 2 PbO + 2 SO 2
Amphoteric is derived from the Greek word amphoteroi (ἀμφότεροι) meaning "both". Related words in acid-base chemistry are amphichromatic and amphichroic , both describing substances such as acid-base indicators which give one colour on reaction with an acid and another colour on reaction with a base.
Lead sesquioxide, Pb 2 O 3, which is a lead (II,IV) oxide as well (lead(II) metaplumbate(IV) [Pb 2+][PbO 2− 3]), reddish yellow Pb 12 O 19 , monoclinic, dark-brown or black crystals The so-called black lead oxide , which is a mixture of PbO and fine-powdered Pb metal and used in the production of lead–acid batteries .
Lead dioxide is used as an anode material in electrochemistry. β-PbO 2 is more attractive for this purpose than the α form because it has relatively low resistivity, good corrosion resistance even in low-pH medium, and a high overvoltage for the evolution of oxygen in sulfuric- and nitric-acid-based electrolytes.
2 PbO + PbS → 3 Pb + SO 2. Metallic lead is attacked (oxidized) only superficially by air, forming a thin layer of lead oxide that protects it from further oxidation. The metal is not attacked by sulfuric or hydrochloric acids. It dissolves in nitric acid with the evolution of nitric oxide gas to form dissolved Pb(NO 3) 2. 3 Pb + 8 H + + 8 NO −
4 Pb + SO 2 → R 3 PbO(SO)R R 3 PbCl + 1/2Ag 2 O (aq) → R 3 PbOH + AgCl R 2 PbCl 2 + 2 OH − → R 2 Pb(OH) 2 + 2 Cl −. R 2 Pb(OH) 2 compounds are amphoteric. At pH lower than 8 they form R 2 Pb 2+ ions and with pH higher than 10, R 2 Pb(OH) 3 − ions. Derived from the hydroxides are the plumboxanes: 2 R 3 PbOH + Na → (R 3 Pb) 2 O ...
Few inorganic lead(IV) compounds are known. They are only formed in highly oxidizing solutions and do not normally exist under standard conditions. [76] Lead(II) oxide gives a mixed oxide on further oxidation, Pb 3 O 4. It is described as lead(II,IV) oxide, or structurally 2PbO·PbO 2, and is the best-known mixed valence lead compound.
Lead(II,IV) oxide is lead(II) orthoplumbate(IV) [Pb 2+] 2 [PbO 4− 4]. [3] It has a tetragonal crystal structure at room temperature, which then transforms to an orthorhombic (Pearson symbol oP28, Space group Pbam, No. 55) form at temperature 170 K (−103 °C). This phase transition only changes the symmetry of the crystal and slightly ...