to write a post about phosphorus (and more specifically - white phosphorus) led me mates NKCh reflections about the following experiences that describe on Facebook. The experience is called the Barking Dog (in the plural, of course, dogs ;). About the same experience, however a bit later;)
Let us, therefore, a bit more carefully this variant alotropowej this element;) crystalline white phosphorus consists of tetrahedral units P 4 . Although described as a basic form of phosphorus, it is in fact metastable. Its reactivity is associated with high stress angle in the molecule P 4 (the angles between the bonds equal to 60 of ). White phosphorus is a solid waxy consistency, soft enough that it can be cut with a knife. At low temperatures it becomes brittle. It is possible distillation white phosphorus with steam. The moist air is oxidised, which owes its characteristic green luminescence (chemiluminescence). In this reaction creates a P 4 About 8 and small amounts of About 3 .
White phosphorus is dissolved in benzene, PCl 3 , PBR 3 , ether, turpentine, fats, S 2 Cl 2 and particularly well in CS 2 (880 g P 4 / 100 g of CS 2 ). The water is completely insoluble, so it was that kept him solvent to prevent oxidation. Flash point P 4 is low - approximately 60 of C, however, contaminated can ignite even at 34 of C. The combustion process creates a P 4 About 10 (in case of shortage of air - P 4 About 6 ). Burning phosphorus is extremely dangerous - is broken and causes intense pain, deep burns, which heal very difficult. It is used for the construction of incendiary bombs that wreak havoc on large and which are unfortunately still are used to today. Example burns from P 4 can see (at your own risk, the view is not pleasant to the eyes) at this address:
White phosphorus is dissolved in benzene, PCl 3 , PBR 3 , ether, turpentine, fats, S 2 Cl 2 and particularly well in CS 2 (880 g P 4 / 100 g of CS 2 ). The water is completely insoluble, so it was that kept him solvent to prevent oxidation. Flash point P 4 is low - approximately 60 of C, however, contaminated can ignite even at 34 of C. The combustion process creates a P 4 About 10 (in case of shortage of air - P 4 About 6 ). Burning phosphorus is extremely dangerous - is broken and causes intense pain, deep burns, which heal very difficult. It is used for the construction of incendiary bombs that wreak havoc on large and which are unfortunately still are used to today. Example burns from P 4 can see (at your own risk, the view is not pleasant to the eyes) at this address:
oparzy When the P 4 in the laboratory or in the course of chemical experiments, it should be skin wash 1% aqueous solution of CuSO 4 or 10% aqueous KMnO 4 , then rinse plenty of water. Absolutely can not apply any ointment to burns, because as I mentioned earlier, P 4 dissolves very well in the fat, which carries a risk of poisoning with phosphorus.
white phosphorus is extremely toxic substance. The dose of 100 mg (when absorbed by inhalation) may lead to death through liver damage. Prolonged contact with the vapor P 4 is also very harmful. In the nineteenth century, workers working in factories experienced match condition (the only seemingly innocent term phossy light , and formally phosphor jaw necrosis ), which, by deposition of phosphorus in the jaw bone, resulted in terrible pain (including teeth and gums) and the deformation of the face, and as a result of further complications and body burden-death.
White phosphorus reacts rapidly with all the halogens to give the compounds of formula PX 3 (x = F, Cl, Br, I) and PX 5 (X = F, Cl, Br). Concentrated nitric acid oxidizes P 4 to H 3 PO 4 :
3P 4 + 20 HNO 3 + 8H 2 O -> 12 H 3 PO 4 + 20 NO
reaction with hot, aqueous NaOH occurs as follows:
P 4 + 3 NaOH + 3 H 2 O -> 3 NaH 2 PO 2 + PH 3
This process also formed small amounts of H 2 and P 2 H 4 . Interesting are the reactions of P 4 of LiPH 2 . Depending on the molar ratio of reactants, obtained by a variety of complex anions phosphides, such as
23 P 4 + 12 LiPH 2 -> 6 Li 2 P 16 + 8 PH 3
Figures below shows the structure of anions [P 16 ] 2 - and [P 21 ] 3 - .
It is also interesting, that phosphorus was jealous of his ability lżejszemu azotowi pal and also can act as a ligand in the complex compounds:) Here are a few original examples:
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