Pyrophosphorsure Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R22:Gesundheitssch?dlich beim Verschlucken.
R34:Verursacht Ver?tzungen.
S-S?tze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
Beschreibung
Pyrophosphoric acid, also known under the name
diphosphoric acid, is colorless, odorless, hygroscopic
and is soluble in water, diethyl ether and ethyl alcohol.
It is produced from phosphoric acid by dehydration.
Pyrophosphoric acid slowly hydrolyzes in the presence
of water into phosphoric acid.
H4P2O7 +H2O?2H3PO4
Upon heating, phosphoric acid loses water, being
converted successively, and to some extent concurrently,
into the pyro- and meta-acids:
2H3PO4?H4P2O7 +H2O
nH3PO4?(HPO3)n + [H2O]n
Chemische Eigenschaften
White to very pale yellow glassy solid
Physikalische Eigenschaften
Colorless needles or liquid; hygroscopic. Crystallizes in two anhydrous forms: a metastable form melting at 54.3°C and a second and more stable form melting at 71.5°C; extremely soluble in cold water, reacting very slowly to form phosphoric acid; decomposing much faster in hot water; very soluble in alcohol and ether.
Verwenden
Pyrophosphoric Acid has been shown to enhance the rate of pyrophosphate hydrolysis by nonenzymatic catlysis and by inorganic pyrophoshatase. Pyrophosphoric Acid can be used for the preparation of vanadyl pyrophosphato methoxide cluster anion. Pyrophosphoric Acid is used in anion binding of inorganic phosphates due to is ability to form complexes.
synthetische
According to early investigators, the pyro-acid is
formed as low as 100 °C, and the conversion is complete
between 255 and 260 °C. Phosphorous oxychloride
reacts with phosphoric acid in the following manner:
5H3PO4 + POC13?3H4P2O7 + 3HC1
A mixture of the ortho- and meta-acids may be
condensed together to form the pyro-acid by heating on the water bath:
nH3PO4 +[HPO3]n?[H4P2O7]n
Definition
ChEBI: An acyclic phosphorus acid anhydride obtained by condensation of two molecules of phosphoric acid.
Pyrophosphorsure Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
