What is Phosphorus?


Advertisements
Advertisements

Related Posts:


Two photos and two diagrams are shown and labeled “a,” “b,” “c,” and “d.” Photo a shows a test tube that contains a solid yellow compound. Diagram b shows a four-sided pyramid shape that has an atom at each corner. Photo c shows a dark black powder in a watch glass. Diagram d shows two four-sided pyramid shapes that have an atom at each corner and are connected together by a single bond.
Figure 1. (a) Because white phosphorus bursts into flame in air, it is stored in water. (b) The structure of white phosphorus consists of P4 molecules arranged in a tetrahedron. (c) Red phosphorus is much less reactive than is white phosphorus. (d) The structure of red phosphorus consists of networks of P4 tetrahedra joined by P-P single bonds. (credit a: modification of work from http://images-of-elements.com/phosphorus.php)

What is Phosphorus? (Openstax Chemistry 2e)

The name phosphorus comes from the Greek words meaning light bringing. When phosphorus was first isolated, scientists noted that it glowed in the dark and burned when exposed to air. Phosphorus is the only member of its group that does not occur in the uncombined state in nature; it exists in many allotropic forms. We will consider two of those forms: white phosphorus and red phosphorus.

White phosphorus is a white, waxy solid that melts at 44.2 °C and boils at 280 °C. It is insoluble in water (in which it is stored—see Figure 1), is very soluble in carbon disulfide, and bursts into flame in air. As a solid, as a liquid, as a gas, and in solution, white phosphorus exists as P4 molecules with four phosphorus atoms at the corners of a regular tetrahedron, as illustrated in Figure 1. Each phosphorus atom covalently bonds to the other three atoms in the molecule by single covalent bonds. White phosphorus is the most reactive allotrope and is very toxic.

Heating white phosphorus to 270–300 °C in the absence of air yields red phosphorus. Red phosphorus (shown in Figure 1) is denser, has a higher melting point (~600 °C), is much less reactive, is essentially nontoxic, and is easier and safer to handle than is white phosphorus. Its structure is highly polymeric and appears to contain three-dimensional networks of P4 tetrahedra joined by P-P single bonds. Red phosphorus is insoluble in solvents that dissolve white phosphorus. When red phosphorus is heated, P4 molecules sublime from the solid.

Source:

Flowers, P., Theopold, K., Langley, R., & Robinson, W. R. (2019, February 14). Chemistry 2e. Houston, Texas: OpenStax. Access for free at: https://openstax.org/books/chemistry-2e

Advertisements
Advertisements

Related Research

Research Article: Eco-Stoichiometric Alterations in Paddy Soil Ecosystem Driven by Phosphorus Application

Date Published: May 7, 2013 Publisher: Public Library of Science Author(s): Xia Li, Hang Wang, ShaoHua Gan, DaQian Jiang, GuangMing Tian, ZhiJian Zhang, Jose Luis Balcazar. http://doi.org/10.1371/journal.pone.0061141 Abstract: Agricultural fertilization may change processes of elemental biogeochemical cycles and alter the ecological function. Ecoenzymatic stoichiometric feature plays a critical role in global soil carbon (C) metabolism, driving … Continue reading

Research Article: Effect of phosphorus stress on Microcystis aeruginosa growth and phosphorus uptake

Date Published: March 22, 2017 Publisher: Public Library of Science Author(s): Sajeela Ghaffar, R. Jan Stevenson, Zahiruddin Khan, Jean-François Humbert. http://doi.org/10.1371/journal.pone.0174349 Abstract: This study was designed to advance understanding of phosphorus regulation of Microcystis aeruginosa growth, phosphorus uptake and storage in changing phosphorus (P) conditions as would occur in lakes. We hypothesized that Microcystis growth … Continue reading

Research Article: Effect of dietary phosphorus intake and age on intestinal phosphorus absorption efficiency and phosphorus balance in male rats

Date Published: November 19, 2018 Publisher: Public Library of Science Author(s): Colby J. Vorland, Pamela J. Lachcik, Loretta O. Aromeh, Sharon M. Moe, Neal X. Chen, Kathleen M. Hill Gallant, Nick Ashton. http://doi.org/10.1371/journal.pone.0207601 Abstract: Intestinal phosphorus absorption is an important component of whole-body phosphorus metabolism, and limiting dietary phosphorus absorption is particularly of interest as … Continue reading