sâmbătă, 6 aprilie 2013

PHOSPHORIC

             PHOSPHORIC - PROPERTIES AND USES

                                                                                                  Symbol: P, Z = 15,
                                                                                                  Atomic mass: 0.974Natural state.

          Phosphorus is not free in nature because of its affinity for oxygen. However, there are a large number of phosphates. Fosforitul considered before a diphosphate, tricalcium phosphate, Ca3 (PO4) 2 is a mixture of hydroxyl - apatite 3Ca3 (PO4) 2 • Ca (HCO3) OH. It has a gray color, sometimes yellow or black, indicating the presence of bitumen.Natural phosphates are classified into three categories namely phosphate phosphorus odd mineral origin, guano, which comes from putrefaction dijecţiilor and seabird corpses; Caprolitele, from animal droppings of reptiles.No topsoil containing phosphoric acid. Successive crops impoverish the soil. In plants, phosphorus pass from animals and humans. Phosphoric acid is available in small amounts of rock. The ovens high phosphorus released, modify the properties of the products. Some coal, oil, sea water, hail may contain phosphorus. Hair jaws, the teeth and bones of vertebrates, in particular in the form of the carbonate containing phosphorus - apatite. Urine contains phosphate 2-3g / l Nuclein, lecithin brain contain more phosphorus fiction.Production:Phosphorus is obtained only from animal bones or industrial mineral phosphates. Bones contain 25-30% ossein, 52-68% Ca3 (PO4) 2, 0-2% Mg3 (PO4) 2, CaCO3 and other salts 2-10% to 2%.The French chemist process is destroyed Oslin red sticks burning alive. The ash is sprayed. It contains 40% of P2O5 and other metal oxides of Fe, Al. The ash is mixed with warm water and treated with sulfuric acid to calcium sulfate is filtered off:Ca3 (PO4) 2 + 2H2SO4 = 2CaSO4 + CaH4 (PO4) 2The liquid was evaporated to a syrup is mixed with coal and calcined to convert the calcium diphosphate tetrahidrocalcic in dimetafosfat:CaH4 (PO4) 2 = Ca (PO3) 2 + 2H2ODistillation phosphorus starts at 750 ° C and ends at 1200 º C:3Ca (PO3) 2 + 10C = P4 + Ca3 (PO4) 2 + 10CO2Ca (PO3) 2 + 5C = P2 + + 5CO Ca2P2O7Vapor condenses in apă.Proprietăţi Physical neutral phosphorus atom has the following electron configuration:1022s22p63s23p3Solid phosphorus is colorless and transparent, flexible and soft. Under the influence of light turns into an opaque white mass. Sublimation of the carbon disulfide solution, white phosphorus is deposited in a crystalline form.
Chemical properties:
       Unlike nitrogen, phosphorus is of great reactivity. The stability and form oxides of nitrogen differs oxiacizilor. The reaction of the metals and non-metals phosphorus results in four types of compounds:Volatile phosphine, phosphine ionic, covalent phosphine, phosphine metal type;White phosphorus reacts with almost all non-metals. He very weak green light in the darkness. Chemical properties of red phosphorus are white phosphorus but more muted. He reacts with sulfur less violent than the white. Phosphorus black is less resistant than the red chemically.Physiological Properties: White phosphorus is a powerful poison.
 
Uses:        Phosphorus helps manufacture red matchsticks. Were prepared pasta with white phosphorus for destruction mice. Preparation of consuming chlorinated phosphorus compounds. Red phosphorus is used to fill fire and smoke projectiles. Phosphoric acid and then converted into phosphate Amon, it serves as a fertilizer.Combinations of phosphorus with hydrogen:Exactly known: hydrogen phosphide or phosphine gas PH3, P2H3 or disofina liquid hydrogen phosphide.Phosphine is a colorless gas with the smell of rotten fish or garlic. In combination with hidroacizii form salts may be mentioned phosphonium chloride phosphonium bromide, phosphonium iodide, phosphonium and phosphonium sulphate.Combinations of phosphorus with halogens:Phosphorous fluorides obtained by distilling fluoride, lead or mercury in the presence of phosphorus:AsF3 + + PF3 PCL3 = AsCl3Phosphorus chlorides:       A mixture is prepared by subjecting the effluence of phosphorus trichloride and hydrogen. Phosphorus trichloride is obtained by the action of chlorine on white and red phosphorus in excess of that of condensation is separated by rectification into a cooled vessel.Phosphorus pentachloride a white solid crystallized. Reacts with strong metal chlorides, Tetro and pentavalent.Bromides of phosphorus is also obtained as follows: phosphorus tribromide and phosphorus pentabromide. Is known and a large number of oxyhalides: Oxitrifluorura of phosphorus trichloride oxide of phosphorus, phosphorus Oxitribromura.Combinations of phosphorus with oxygen: phosphorus oxides: Diphosphorus P4O6Dioxidul phosphorus trioxide P8O16 is a solid crystalline phosphoric incolorAnhidrida P4O10.In 1669, a merchant in Hamburg chemicals, military and then the doctor was named Hennig Brand, was also among enthusiasts seeking alchemical research, as hundreds of his predecessors, "FILOZOALA stone" and "elixir of life". So he thought to look for "philosopher's stone" even the man himself, making the following experiment: a boiled human urine in the absence of air a really brilliant idea, and distilled in the presence of sand tens of liters, maybe hundreds until remaining liquid focused, became mushy, and after he left and did cool air to enter the distillation flask to his great surprise, there was a great light, which he called "cold fire". This discovery of Brand was the most spectacular of all alchemical period. The symbol P is assigned to the phosphorus by item name in Greek "Phosphoros" which means light bearer (a variety of phosphorus is phosphorescent emit light). Etymology: phos = light, pherein = to wear.The first matches containing white phosphorus in their pin and fires by rubbing on a rough surface. They were abandoned because of their toxicity and replaced with Swedish matches that have pins made of potassium chlorate and antimony sulphide, flammable, ignite by rubbing on a paste containing red phosphorus.Phosphorus can exist free in nature because it has a high affinity for oxygen. It is found only in the form of compounds (organic and inorganic), especially phosphate. The main mineral containing phosphorus is apatite, which under the action of atmospheric slow, turns in phosphorus and is found in the Earth's crust. Phosphorus is in the body of plants and animals in the form of inorganic combinations (shell shells, bones of vertebrates) and as organic compounds (blood, brain, hair, muscle fibers, egg yolk, cabbage, cauliflower, milk, cheese).In industry, phosphorus is made of calcium phosphate by calcination (heating to 1000 ° C) with silica and coal. 14Phosphorus occurs in several allotropic modificatii fundamental due to the different number of atoms in the molecule. The most important and most common allotropic forms of phosphorus are white phosphorus and red phosphorus.White PhosphorusWhite phosphorus in solid and liquid molecule is composed of four phosphorus atoms united by covalent bonds between them, which occupy the vertices of a regular tetrahedron. Valence angles of 60 ° are small and indicate a considerable strain of the molecule, which is consistent with the great reactivity of white phosphorus. In the crystal, molecules are linked by strong phosphorus weak Van der Waals type, which explain some properties of white phosphorus.


Properties: KI  

   - The solid, crystalline, transparent, yellow-white color;
    
- Is softened, the wax-like density of 1.8g/cmc and a melting point of 44 ° C;
    
- Garlic odor vapor form, is a good insulator, and because of fat solubility is toxic, causing burns;     - Emits light green, very weak in the dark, in the presence of atmospheric oxygen and moisture, oxidation phenomenon stems largely inferior product of oxidation of phosphorus and chemioluminiscenta called;- Has high chemical reactivity and turns in the air at 60 ° C because of the ease with which light, white phosphorus is stored underwater.Phosphorus in everyday life-Physiological role: White Phosphorus, being fat soluble, it is very poisonous. With high affinity for oxygen cause the disappearance of the blood and into the stomach produces vomiting with pain and death. Is recommended as an antidote magnesium oxide, copper sulfate and the like;-Being poisonous, phosphorus is used in small quantities to obtain the pesticides for eradication of rats;-In metallurgy, white phosphorus is added in some alloys corrosion;-Is used in the manufacture of:Phosphoric acid and fertilizer phosphorus (used in agriculture);-Paste from match boxes;-Halides of phosphorus and organic dyes;Red phosphorous is used in pyrotechnics (explosives industry);