| Physical Properties | Colorless orthorhombic crystals or white powder; converts to cubic form at 316°C; density 8.445 g/cm3 (orthorhombic form) and 7.750 g/cm3 (cubic form); melts at 855°C; vaporizes at 1,290°C; slightly soluble in water (640 mg/L at 20°C); KSP 7.12x10–7 at 25°C; soluble in nitric acid; insoluble in acetone and ammonia.
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| Uses | Lead difluoride is used in low melting glasses; in glass coatings to reflect infrared rays; in phosphors for television-tube screens; for nickel plating on glass; and as a catalyst for the manufacture of picoline.
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| Preparation | Lead difluoride can be prepared by several methods. It is obtained by treating lead hydroxide or lead carbonate with hydrofluoric acid, followed by evaporation of the solution:
Pb(OH)2 + 2HF → PbF2 + 2H2O
Alternatively, it is precipitated by adding hydrofluoric acid to a lead(II) salt solution; or adding potassium fluoride to lead nitrate solution:
2KF + Pb(NO3)2 → PbF2 + 2KNO3
Lead difluoride also can be directly synthesized from its elements, by the action of lead with fluorine.
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| Toxicity | Slightly to moderately toxic by ingestion and subcutaneous routes. The oral LD50 in rats is around 3,000 mg/kg.
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| Chemical Properties | Lead fluoride is a white to colorless, odorless
crystalline (rhombic, orthorhombic) solid |
| Uses | Lead(II) fluoride is used in fuses, glass coatings to reflect infrared rays and phosphors for television screens and in low melting glasses. Further, it serves as a catalyst for the preparation of picoline. |
| General Description | Odorless white solid. Sinks in water. |
| Reactivity Profile | Calcium carbide mixed with Lead fluoride , at ordinary temperatures, becomes incandescent [Mellor 5:862-64. 1946-47]. |
| Health Hazard | Not irritating to skin or mucuous membranes; protect against chronic poisoning. Early symptoms of lead intoxication via inhalation or ingestion are most commonly gastrointestinal disorders, colic, constipation, etc.; weakness, which may go on to paralysis chiefly of the extensor muscles of the wrists and less often the ankles, is noticeable in the most serious cases. Ingestion of a large amount causes local irritation of the alimentary tract; pain, leg cramps, muscle weakness, paresthesias, depression, coma, and death may follow in 1 or 2 days. Contact with eyes causes irritation. |
| Fire Hazard | Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. |
| Potential Exposure | Used to make other chemicals, underwater paints; electronic and optical parts (for growing
single-crystal, solid-state lasers); in high-temperature dryfilm lubricants; and making special grades of glass. |
| Shipping | UN3288 Toxic solids, inorganic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical
Name Required. UN2291 Lead compounds, soluble n.o.s.,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials,
Technical Name Required |
| Incompatibilities | Violent reaction with oxidizers, chemically active metals; calcium carbide. May ignite combustibles, such as wood, paper, oil, etc |
