General Description
Brown, hexagonal crystals. Insoluble in water. Used in matches, explosives, electrodes.
Reactivity Profile
LEAD DIOXIDE(1309-60-0) is a strong oxidizing agent. Noncombustible but accelerates the burning of combustible material. Reacts violently with hydrogen sulfide [Bretherick 1979. p. 977-978]. Ignites with hydroxylamine [Mellor 8:291. 1946-47]. Reacts violently with hydrogen peroxide [Mellor 1:937 1946-47], with phenylhydrazine [Mellor 7:637 1946-47], or with sulfuryl chloride [Mellor 10:676. 1946-47]. Reacts with incandescence with sulfur dioxide [Mellor, 1941, Vol. 7, 689]. Explodes when ground with boron or yellow phosphorus [Mellor, 1946, Vol. 5, 17]. Mixtures with sulfur and red phosphorus ignite [Mellor, 1941, Vol. 7, 689]. Reacts vigorously when heated with calcium sulfide, strontium sulfide or barium sulfide [Mellor, 1941, Vol. 3, 745].
Air & Water Reactions
Insoluble in water.
Health Hazard
Toxic by ingestion. Inhalation of dust is toxic. Fire may produce irritating, corrosive and/or toxic gases. Contact with substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause pollution.
Potential Exposure
This material is used in electrodes for
lead-acid batteries; in matches; explosives, and as a curing
agent for polysulfide elastomers
Fire Hazard
These substances will accelerate burning when involved in a fire. May explode from heat or contamination. Some may burn rapidly. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at
least 15 minutes, occasionally lifting upper and lower
lids. Seek medical attention immediately. If this chemical
contacts the skin, remove contaminated clothing and
wash immediately with soap and water. Seek medical
attention immediately. If this chemical has been inhaled,
remove from exposure, begin rescue breathing (using
universal precautions, including resuscitation mask) if
breathing has stopped and CPR if heart action has
stopped. Transfer promptly to a medical facility. When
this chemical has been swallowed, get medical attention.
Give large quantities of water and induce vomiting. Do
not make an unconscious person vomit
Shipping
UN1872 Lead dioxide, Hazard Class: 5.1;
Labels: 5.1-Oxidizer.
Incompatibilities
Lead dioxide is a powerful oxidizer.
Violent reaction with many compounds, including reducing
agents; chemically active metals; combustible materials,
strong acids, alkaline earth sulfides, aluminum carbides,
aluminum, amines, calcium sulfide, carbides, chlorine trifluoride, glycerin, hydrides, hydrochloric acid, hydrogen
peroxide, hydrogen sulfide, hydroxylamine, magnesium,
metal powders, metal sulfides, molybdenum, phenylhydrazine, phosphorous red/friction, phosphorous trichloride, silicon, sulfides, sulfur, sulfur dioxide, sulfur/friction, sulfuric
acid, tungsten, hydrogen trisulfide
Description
Lead dioxide, PbO2, also plumbic oxide, is an odorless dark-brown crystalline powder which is nearly insoluble in water. It exists in two crystalline forms. The a phase has orthorhombic symmetry, lattice constants a=0.497 nm, b=0.596 nm, c= 0.544 nm, Z=4 (four formula units per unit cell).
Chemical Properties
brown to black powder
Chemical Properties
Lead dioxide is a dark brown crystalline solid
or powder.
Waste Disposal
Conversion to soluble salt,
precipitation as sulfide and return to supplier. Do not discharge into drains or sewers. Dispose of waste material as
hazardous waste using a licensed disposal contractor to an
approved landfill. Consult with environmental regulatory
agencies for guidance on acceptable disposal practices.
Containers must be disposed of properly by following package label directions or by contacting your local or federal
environmental control agency, or by contacting your
regional EPA office.
Physical properties
Red tetragonal crystals or brown powder; density 9.64 g/cm3; decomposes on heating at 290°C; practically insoluble in water; also insoluble in alkalis; moderately soluble in hydrochloric acid and also, in nitric acid-hydrogen peroxide mixture; slowly dissolves in acetic acid.
Occurrence
Lead dioxide occurs in nature as the mineral plattnerite. It is used as an oxidizing agent in manufacturing dyes and intermediates. It also is used as a source of oxygen in matches, pyrotechnics, and explosives. In matches, the oxide is combined with amorphous phosphorus as an ignition surface. It also is used in making lead pigments, liquid polysulfide polymers and rubber substitutes. Lead dioxide electrodes are used in lead storage batteries in which lead dioxide accumulates on positive plates.
Preparation
Lead dioxide is produced by oxidizing an alkaline slurry of lead monoxide with chlorine, sodium hypochlorite, or bleaching powder. Alternatively, it is obtained by passing chlorine into a hot aqueous suspension of lead sulfate and magnesium hydroxide. The ionic reaction is:
Pb(OH)3ˉ +ClOˉ → PbO2 + Clˉ+ OHˉ + H2O
It also is produced by electrolysis of acidic solutions of lead salts using a lead or platinum electrode. In such electrolytic process, lead dioxide is deposited on the anode of the cell.
Insoluble powdered lead dioxide also may be obtained when lead tetroxide is heated with nitric acid:
Pb3 O4 + 4HNO3 → 2Pb(N)3)2 + PbO2 + 2H2O
Lead dioxide also can be prepared by fusing lead monoxide with a mixture of sodium nitrate and sodium chlorate.
storage
Color Code—Yellow: Reactive Hazard; Store in alocation separate from other materials, especially flammables and combustibles. Prior to working with this chemical you should be trained on its proper handling andstorage. Lead dioxide must be stored to avoid contact withoxidizers (such as perchlorates, peroxides, permanganates,chlorates and nitrates) chemically active metals (such aspotassium, sodium, magnesium and zinc), since violentreactions occur. Store in tightly closed containers in a cool,well-ventilated area away from combustible materials, suchas wood, paper, and oil. Lead dioxide is regulated byOSHA Standard 1910.1025. All requirements of the standard must be followed. See OSHA Standard 1910.104 andNFPA 43A Code for the Storage of Liquid and SolidOxidizers for detailed handling and storage regulations.