Iron (III) phosphate

Structural formula
General
Surname	Iron (III) phosphate
other names	Iron orthophosphate Ferric phosphate Ferrum phosphoricum Ferrum phosphoricum oxydatum
Molecular formula	FePO 4
Brief description	yellowish white odorless solid
External identifiers / databases
CAS number 10045-86-0 EC number 233-149-7 ECHA InfoCard 100.030.123 PubChem 24861 Wikidata Q1311179
properties
Molar mass	150.83 g mol −1
Physical state	firmly
density	2.87 g cm −3
Melting point	500 ° C (decomposes to iron (III) oxide)
solubility	Slightly soluble in water
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Iron (III) phosphate is a chemical compound from the group of phosphates , more precisely iron phosphates . It also comes in several hydrated forms FePO ₄  ·  n  H ₂ before O, and from 140 ° C, the crystal water is discharged.

Occurrence

Iron (III) phosphate also occurs naturally in the soil (e.g. as the mineral strictite ). When phosphates (from fertilizers) are introduced into water, iron (III) phosphate is naturally also formed.

Extraction and presentation

Iron (III) phosphate can be prepared by reaction of ferrous hydroxide and phosphoric acid or of iron (III) chloride and disodium hydrogen phosphate are presented

${\displaystyle \mathrm {FeCl_{3}+Na_{2}HPO_{4}\rightarrow FePO_{4}\downarrow +\ 2\ NaCl+HCl} }$

use

Iron (III) phosphate is used as an active ingredient in pesticides ( against snails , i.e. as a molluscicide ), and in pharmaceuticals, the food industry and ceramics.

If lithium iron phosphate accumulators are fully charged, the electrodes on the positive pole side essentially consist of anhydrous iron (III) phosphate FePO ₄ . This absorbs lithium ions when the battery is discharged and is thereby converted into lithium iron phosphate LiFePO ₄ :

${\displaystyle \mathrm {FePO_{4}+Li^{+}+e^{-}\longrightarrow LiFePO_{4}} +{\text{elektrische Energie}}}$

Related links

• Iron (II) phosphate
• Iron diphosphate
• Iron (III) hydroxophosphate

Individual evidence

1. ↑ ^{a b} Heinrich Remy: Textbook of Inorganic Chemistry Volume II, Leipzig 1973, page 373.
2. ↑ ^{a b c} Entry on iron (III) phosphate in the GESTIS substance database of the IFA , accessed on December 22, 2019(JavaScript required) .
3. ↑ ^{a b} EU assessment report iron (III) phosphate - Legal regulations of the European Union on plant protection products and their active ingredients, Volume D 33.
4. ^ Strengite (Mineral Atlas) .
5. ↑ Rehabilitation of ponds and lakes ( memento of the original from November 25, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 
6. ↑ Microbially catalyzed redox reactions and geochemistry of iron compounds in the Lake Constance sediment .
7. ↑ Measures against the snail plague (Federal Environment Agency) .