Phosphinic acid
Structural formula | |||||||||||||||||||
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General | |||||||||||||||||||
Surname | Phosphinic acid | ||||||||||||||||||
other names |
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Molecular formula | H 3 PO 2 | ||||||||||||||||||
Brief description |
colorless and odorless leaflets |
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properties | |||||||||||||||||||
Molar mass | 66,00 g · mol -1 | ||||||||||||||||||
Physical state |
firmly |
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density |
1.49 g cm −3 |
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Melting point |
26.5 ° C |
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boiling point |
108 ° C (decomposition) |
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Vapor pressure |
0.43 Pa (25 ° C) |
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pK s value |
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solubility |
soluble in water |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Phosphinic acid , also known as hypophosphorous acid out of date , is one of the acids of phosphorus and has the empirical formula H 3 PO 2 . Their salts are called phosphinates or (outdated) hypophosphites ; With alcohols , phosphinic acid can formally form phosphinic acid esters . The phosphorus in these compounds has the oxidation state + I.
Manufacturing
Phosphinic acid can be produced by disproportionation of white phosphorus (P 4 ) in an alkaline medium:
It is also possible to display it by decomposing barium hypophosphite with sulfuric acid .
properties
Anhydrous hypophosphorous acid crystallizes in colorless flakes, which dissolve very easily in water. When heated to 130–140 ° C, disproportionation to monophosphine and phosphonic acid occurs .
use
In aqueous solution, hypophosphorous acid can be used as a reagent for reducing diazonium groups ( dediazonation ). Elemental nitrogen and phosphorous acid are formed as reaction products .
See also
literature
- AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 764.
Individual evidence
- ↑ a b c d e f g Entry on phosphinic acid in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
- ↑ Registration dossier on phosphinic acid (section Vapor pressure ) at the European Chemicals Agency (ECHA), accessed on June 14, 2017.
- ↑ a b chem.wisc.edu: pKa Data , Compiled by R. Williams (PDF, 78 kB).
- ↑ a b Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 539.