Search results
Results From The WOW.Com Content Network
The general formula of a phosphoric acid is H n+2−2x P n O 3n+1−x, where n is the number of phosphorus atoms and x is the number of fundamental cycles in the molecule's structure, between 0 and n + 2 / 2 . Pyrophosphate anion. Trimethyl orthophosphate.
In biological systems, phosphorus can be found as free phosphate anions in solution (inorganic phosphate) or bound to organic molecules as various organophosphates. Inorganic phosphate is generally denoted P i and at physiological (homeostatic) pH primarily consists of a mixture of [HPO 4] 2− and [H 2 PO 4] − ions.
The most prevalent compounds of phosphorus are derivatives of phosphate (PO 4 3−), a tetrahedral anion. [45] Phosphate is the conjugate base of phosphoric acid, which is produced on a massive scale for use in fertilisers. Being triprotic, phosphoric acid converts stepwise to three conjugate bases:
The difference between successive pK a values is sufficiently large so that salts of either monohydrogen phosphate, HPO 2− 4 or dihydrogen phosphate, H 2 PO − 4, can be prepared from a solution of phosphoric acid by adjusting the pH to be mid-way between the respective pK a values.
Between 1913 and 1950 radium-228 and radium-226 were used to activate a phosphor made of silver doped zinc sulfide (ZnS:Ag), which gave a greenish glow. The phosphor is not suitable to be used in layers thicker than 25 mg/cm 2, as the self-absorption of the light then becomes a problem. Furthermore, zinc sulfide undergoes degradation of its ...
Phosphate esters bearing P-OH groups are acidic. The pKa of the first OH group is typically between 1-2, while the second OH deprotonates at a pKa between 6-7. [21] As such, phosphate mono- and di-esters are negatively charged at physiological pH. [22]
[2] [3] "Phosphoryl" groups are covalently bonded by a single bond to an organic molecule, phosphate group(s) or another "phosphoryl" group(s), and those groups are sp 3 hybridized at the phosphorus atom. [4] The term "phosphoryl" in the mentioned branches is usually used in the description of catalytic mechanisms in living organisms.
This combustion gives phosphorus(V) oxide, which consists of P 4 O 10 tetrahedral with oxygen inserted between the phosphorus atoms and at their vertices: P 4 + 5 O 2 → P 4 O 10. The odour of combustion of this form has a characteristic garlic smell. White phosphorus is only slightly soluble in water and can be stored under water.