Retrieved from https://studentshare.org/health-sciences-medicine/1498421-placing-white-phosphorus-in-proper-context
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Phosphorus is used to manufacture phosphates which are again used to manufacture fertilizers. Therefore, white phosphorus is itself used as a source of this important material for industrial and military usage. White phosphorus may occur in nature naturally, but only in very small amounts. So the main sources of this material involve human agency and chemical reactions related to metallurgy. White phosphorus consists of tetrahedral phosphorus molecules. “White phosphorus, P4, is produced by reducing apatites Ca5(PO4)3(OH, F, Cl) with high fluoride contents (fluorapatite: >30% P2O5 by weight:2.3-4.8% F, traces of Al, F, Mg, lanthanoids, U, carbonates, etc.) with charcoal and quartzite in an electric furnace at 1400-1500oC” (Inorganic Chemistry 2001, p. 678). In reaction with quartz sand at high temperatures, the apatites’ calcium oxide part from calcium phosphate gives calcium silicate, while the phosphate part is transformed into P2.
With a fall in temperature, this P2 dimerizes and gives rise to P4. This P4, which is white phosphorus, is extremely reactive in the chemical sense and can burn spontaneously even in the presence of normal or below normal level oxygen in the air at room temperatures (Inorganic Chemistry 2001; Felton 1982). (Inorganic Chemistry 2001). Felton (1982), however, pointed out that the problem of phosphorus poisoning due to industrial usage of P4 had been eradicated by the middle of the 20th century, particularly when ammunition industries declined following the World Wars.
Therefore, in modern times, white phosphorus is generally deliberately delivered during times of battles and military tensions. In that case, military power can use aircraft for detonating bomb shells containing the material a little above a targeted civilian area or enemy camp. Phosphorus bombs have been used as incendiary devices in several recent wars including those between NATO and Iraq, Israel and Lebanon, etc. (Human Rights Watch 2009) The context of chemical properties: White phosphorus cannot be artificially obtained without metallurgical knowledge and infrastructure, since it is produced by reducing apatites (ore of calcium phosphate) to P2 molecules at high temperatures and this P2 dimerizes to P4 when cooled.
The material is highly reactive, and in a fine granule state, it may get spontaneously ignited in the presence of room temperature air. In a more compact, solidified form, ignition would occur when temperatures are raised above 50oC. Molten states white phosphorus under water may burn if oxygen gas is supplied into the water by a tube. It happens so since the material has a high chemical affinity with oxygen. Therefore, the material shows reactivity even in moist air giving rise to various acids of phosphorus. About 3000 kJ of heat per mole is released when white phosphorus is oxidized to phosphorus pentoxide. (See Inorganic Chemistry 2001, p. 683)
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