Skip to main content Skip to Search Box

Definition: phosphate from Philip's Encyclopedia

Chemical compounds derived from phosphoric acid (H3PO4). They are used to produce soaps, detergents, and glass. Their use as as fertilizers can cause environmental damage.


Summary Article: phosphate from The Columbia Encyclopedia

salt or ester of phosphoric acid, H3PO4. Because phosphoric acid is tribasic (having three replaceable hydrogen atoms), it forms monophosphate, diphosphate, and triphosphate salts in which one, two, or three of the hydrogens of the acid are replaced, respectively. Because replaceable hydrogens remain in monophosphates and diphosphates, they are sometimes called acid phosphates. The most important inorganic phosphate is calcium phosphate, Ca3(PO4)2. It makes up the larger part of phosphate rock, a mineral that is abundantly distributed throughout the world. Since calcium phosphate is only slightly soluble in water, it is not very suitable as a source of the phosphorus necessary for plant life; however, by treating it with sulfuric acid the soluble calcium acid phosphate known as superphosphate of lime is formed. Other important inorganic phosphates include ammonium phosphate, important as a fertilizer; trisodium phosphate, used in detergents and for softening water; and disodium phosphate, used to some extent in medicine and in preparing baking powders. Various acid phosphates, e.g., those of calcium, magnesium, and sodium, are sometimes present in carbonated beverages. Microcosmic salt, used in certain bead tests in chemical analysis, is sodium ammonium phosphate. Organic phosphates play an important role in metabolism. For example, in the metabolism of sugars (which have hydroxyl groups, −OH, in their molecules), phosphate esters are often formed as an intermediate compound. Formation of these esters is called phosphorylation. Nucleotides are phosphate esters that play an important role in the conservation and use of the energy released in the metabolism of foods in the body; adenosine triphosphate is an important nucleotide. DNA and RNA (see nucleic acid) are complex polymeric organic phosphates.

The Columbia Encyclopedia, © Columbia University Press 2017

Related Credo Articles

Full text Article inosine 5-diphosphate
Hawley's Condensed Chemical Dictionary

([(2R,3S,4R,5R)-3,4-dihydroxy-5-(6-oxo-3H-purin-9-yl)oxolan-2-yl]methyl phosphono hydrogen phosphate). CAS: 81012-88-6. C10H14N4O11P2. An inosine nu

Full text Article phosphate
Britannica Concise Encyclopedia

Any of numerous chemical compounds related to phosphoric acid (H3PO4). Phosphate salts are inorganic compounds containing the phosphate ion (PO43−)

Full text Article phos•phate (P)
Stedman's Medical Dictionary

(fos′fāt). A salt or ester of phosphoric acid. For individual phosphates not listed here, see under the name of the base. bone phosphate ...

See more from Credo