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Red lead

Lead(II,IV) oxide
Sample of pulverised lead(II,IV) oxide
Names
Preferred IUPAC name
Lead tetroxide
Identifiers
1314-41-6 YesY
3D model (Jmol) Interactive image
ChemSpider 21169908 YesY
ECHA InfoCard 100.013.851
EC Number 215-235-6
PubChem 16685188
UN number 1479
Properties
Pb
3O
4
Molar mass 685.6 g mol−1
Appearance Vivid orange crystals
Density 8.3 g cm−3
Melting point 500 °C (decomposition)
Vapor pressure 1.3 kPa (at 0 °C)
Structure
Tetragonal, tP28
P42/mbc, No. 135
Hazards
GHS pictograms The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
H272, H302, H332, H360, H373, H410
P201, P220, P273, P308+313, P501
Toxic T Dangerous for the Environment (Nature) N
R-phrases R61, R20/22, R33, R50/53, R62
S-phrases S53, S45, S60, S61
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Lead(II,IV) oxide, also called minium, red lead or triplumbic tetroxide, is a bright red or orange crystalline or amorphous pigment. Chemically, red lead is Pb3O4, or 2 PbO·PbO2. Pb3O4,is [2PbO].[PbO2] or Lead(II,IV) oxide. It is used in the manufacture of batteries, lead glass and rust-proof primer paints.

Lead(II,IV) oxide has a tetragonal crystal structure at room temperature, which transforms to an orthorhombic (Pearson symbol oP28, Space group = Pbam, No 55) form at temperature 170 K. This phase transition only changes the symmetry of the crystal and slightly modifies the interatomic distances and angles.

Unit cell of tetragonal Pb3O4 (Key:      Pb      O)

Part of tetragonal red lead's crystal structure

Lead(II,IV) oxide is prepared by calcination of lead(II) oxide (also called litharge) in air at about 450 to 480 °C:

The resulting material is contaminated with lead(II) oxide. If a pure compound is desired, PbO can be removed by a potassium hydroxide solution:

Another method of preparation relies on annealing of lead carbonate (cerussite) in air:


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