Presentation on theme: "Phosphorus Atomic Number:15 Atomic Symbol:P Atomic Weight:30.97376 Electron Configuration:[Ne]3s 2 3p 3 History (Gr. phosphoros, light bearing; ancient."— Presentation transcript:
Phosphorus Atomic Number:15 Atomic Symbol:P Atomic Weight:30.97376 Electron Configuration:[Ne]3s 2 3p 3 History (Gr. phosphoros, light bearing; ancient name for the planet Venus when appearing before sunrise) Brand discovered phosphorus in 1669 by preparing it from urine. Date of Discovery: 1669 Discoverer: Hennig Brand Name Origin: From the Greek words phôs (light) and phoros (bearer) Uses: fertilizers, detergents Obtained From: phosphate rock
Phosphors do more than make color CRT displays possible. They are a key technology for applications as diverse as product authentication, toys, and the tagging of biological molecules.
Phosphorus is commonly misspelled "phosphorous". It is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm. Phosphorus exists in several allotropic forms including white (or yellow), red, and black (or violet). White phosphorus has two modifications. Ordinary phosphorus is a waxy white solid. When pure, it is colourless and transparent. It is insoluble in water, but soluble in carbon disulphide. It catches fire spontaneously in air, burning to P 4 O 10, often Details
Phosphorus exists in three allotropic forms: white, black, and red. White phosphorus: Colorless or yellowish, transparent, crystalline solid; darkens on exposure to light; m. 44.1° (vapor press. 0.181 mm.); b. 280° d. 1.83; volatile; sublimes in vacuo. at ordinary temperature when exposed to light. When exposed to air in the dark, emits a greenish light and gives off white fumes. Almost insoluble in water Solubility in oils: one gram phosphorus dissolves in 80 ml. olive oil, 60 ml. oil of turpentine, about 100 ml. almond oil. Ignites at about 30° in moist air; the ignition temperature is higher when the air is dry. Caution: Handle with forceps. Keep under water. Use: Mannf. rat poisons; for smoke screens, gas analysis.
Black phosphorus: Crystals; resembles graphite in texture; produced from the white modification under high pressures: Bridgman,. J. Am. Chem. Sec. 36, 1344 (1914); Jacobs, J. Chem. Phys. 5, 945 (1937). d. 2.691. Does not catch fire spontaneously. Insoluble in organic solvents. Red phosphorus: Red to violet powder; polymorphism: Roth, DeWitt, Smith, J. Am. Chem. Sec. 69, 2881 (1947). Its properties are intermediate between those of the white and black forms. Sublimes at 416°, triple point 589.5° under 43.1 atm. d. 2.34. Insoluble in orgamc solvents. Soluble in phosphorus tribromide. Less active than the white form; reacts only at high temperatures. Yields the white modification when distilled at 290°. Catches fire when heated in air to about 260° and burns with formation of the pentoxide. Burns when heated in an atmosphere of chlorine
uses for phosphorus used in the manufacture of safety matches, pyrotechnics, incendiary shells, smoke bombs, tracer bullets, etc. fertilisers phosphates are used in the production of special glasses, such as those used for sodium lamps bone-ash, calcium phosphate, is used to produce fine chinaware and to produce monocalcium phosphate used in baking powder important in the production of steels, phosphor bronze, and many other products Na 3 PO 4 is important as a cleaning agent, as a water softener, and for preventing boiler scale and corrosion of pipes and boiler tubes pesticides