The phosphorus is a chemical element with symbol P and atomic number 15. Elemental phosphorus exists in two forms principale s, white phosphorus and red phosphorus, but as it is highly reactive, phosphorus is never found as a free element in the earth. It has a concentration in the earth’s crust of about one gram per kilogram (compare copper at about 0.06 grams). With few exceptions, phosphorus-containing minerals are in the maximum oxidized state as inorganic phosphate rocks .
Index
Phosphorus – Characteristics
Elemental phosphorus was first isolated (like white phosphorus) in 1669 and gave off a faint glow when exposed to oxygen. , the planet Venus. The term “phosphorescence,” which means glow after illumination, derives from this property of phosphor, although the word has since been used for a different physical process that produces a glow.
The glow of phosphorus is caused by the oxidation of white phosphorus (but not red), a process now called chemiluminescence . Along with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a nyctogen.
Phosphorus is essential for life . Phosphates (compounds that contain the phosphate ion, PO43-) are a component of DNA, RNA, ATP, and phospholipids. Elemental phosphorus was first isolated from human urine, and bone ash was an important source of phosphate in its early days.
Phosphorus – Benefits
Phosphorus is essential for the health of plants and animals . Many essential chemicals in living cells contain phosphorus. One of the most important chemicals is adenosine triphosphate (ATP). ATP provides cells with the energy they need to stay alive and carry out all the tasks they need to perform.
Phosphorus is critical for the development of bones and teeth . Nucleic acids also contain phosphorus. Nucleic acids are chemicals that perform many functions in living organisms. For example, they carry genetic information in a cell . They tell the cell what chemicals to make. It also acts as the “director” in the formation of those chemicals.
The recommended daily amount of phosphorus for humans is one gram. It’s pretty easy to get that amount of phosphorus every day from meat, milk, beans, and grains.
Metallurgical Aspects
Phosphorus is also an important component in the production of steel , in the manufacture of phosphor bronze and in many other related products. Phosphorus is added to metallic copper during its smelting process to react with oxygen present as an impurity in copper and to produce copper alloys containing phosphorus (CuOFP) with greater resistance to hydrogen embrittlement than normal copper.
Water softening
Sodium tripolyphosphate made from phosphoric acid is used in laundry detergents in some countries , but is prohibited for this use in others. This compound softens water to improve detergent performance and to prevent tube / boiler corrosion.
Several
- Phosphates are used to make special glasses for sodium lamps.
- Bone ash, calcium phosphate, is used in the production of fine porcelain.
- Phosphoric acid made from elemental phosphorous is used in food applications such as soft drinks and as a starting point for food grade phosphates. These include mono calcium phosphate baking powder and sodium tripolyphosphate. Phosphates are used to enhance the characteristics of processed meat and cheese and in toothpaste.
Phosphorus – Uses
In 1996, 91 percent of all phosphate rock mined in the United States was used to make fertilizers . Modern farmers use huge amounts of synthetic (artificial) fertilizers on their crops. This synthetic fertilizer contains nitrogen, phosphorus and potassium, the three critical elements for growing plants.
These elements normally occur in the soil, but may not be present in large enough quantities. Adding them through synthetic fertilizers helps plants grow better. Most farmers add some type of synthetic fertilizer to their fields every year. This demand for synthetic fertilizers represents the largest use of phosphorus compounds.
Phosphorus and its compounds have other uses. These uses account for approximately 10 percent of all phosphorous produced. For example, compounds known as phosphorous pentasulfide (P 2 S 5) and phosphorous sesquisulfide (P 4 S 3) are used to make common safety matches of wood and paper . These compounds cover the tip of the match. When phosphor is scratched on a surface, phosphorous pentasulfide or phosphorous sesquisulfide burns into flames. Light other chemicals in the head of the match.
Matches – Properties
Physical properties
Phosphorus exists in at least three allotropic forms . Allotropes are forms of an element with different physical and chemical properties. The three main allotropes are named by their colors: white phosphorus (also called yellow phosphorous), red phosphorous, and black phosphorous (also called violet phosphorous). All of these allotropes have different physical and chemical properties.
The white phosphorus is a waxy solid and transparent e. Its melting point is 44.1 ° C (111 ° F) and its boiling point is 280 ° C (536 ° F). It has a density of 1.88 grams per cubic centimeter. If held in a vacuum, it sublimates if exposed to light. Sublimation is the process by which a solid changes directly to a gas when heated, without first changing to a liquid.
White phosphorus is phosphorescent. It emits a beautiful greenish-white glow. It does not dissolve well in water, although it does dissolve in other liquids, such as benzene, chloroform, and carbon disulfide. White phosphorus sometimes appears slightly yellowish due to traces of red phosphorous.
F Red is a red powder ósforo . It can be made by heating white phosphorous with a catalyst to 240 ° C (464 ° F). A catalyst is a substance that is used to speed up or slow down a chemical reaction without undergoing any change. Without a catalyst, red phosphorus sublimates at 416 ° C (781 ° F). Its density is 2.34 grams per cubic centimeter. It does not dissolve in most liquids.
The black phosphorus looks like graphite powder . Graphite is a form of carbon that is used in “lead” pencils. Black phosphorus can be made by applying extreme pressure to white phosphorous. It has a density of 3.56 to 3.83 grams per cubic centimeter. One of its interesting properties is that it conducts an electric current despite being a non-metal.
Brand was convinced that the key to transforming metals into gold could be found in urine. Instead, he found phosphorus.
Chemical properties
The white phosphorus is the form which most commonly occurs at room temperature . It is very reactive. It combines with oxygen so easily that it ignites spontaneously (automatically). As a safety measure, white phosphorus is stored underwater in chemical laboratories.
Phosphorus easily combines with halogens . Halogens are the elements that make up Group 17 (VIIA) of the periodic table. They include fluorine, chlorine, bromine, iodine, and astatin.
Phosphorus also combines with metals to form compounds known as phosphides , while white phosphorus combines with oxygen so easily that it ignites automatically. As a safety measure, white phosphorus is stored underwater in chemical laboratories.
Dr. Samantha Robson ( CRN: 0510146-5) is a nutritionist and website content reviewer related to her area of expertise. With a postgraduate degree in Nutrition from The University of Arizona, she is a specialist in Sports Nutrition from Oxford University and is also a member of the International Society of Sports Nutrition.