Sodium ferrioxalate

Last updated
Sodium ferrioxalate
Sodium TrisoxalatoferrateIIIoct.jpg
Names
IUPAC name
Sodium iron(III) oxalate
Other names
Sodium ferrioxalate

Sodium ferric oxalate
Sodium trisoxalatoferrate (III)

Sodium oxalatoferrate

Contents

Identifiers
  • 5936-14-1 Yes check.svgY
  • 555-34-0
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.008.267 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 209-092-9
PubChem CID
  • InChI=1S/3C2H2O4.Fe.3Na/c3*3-1(4)2(5)6;;;;/h3*(H,3,4)(H,5,6);;;;/q;;;+3;3*+1/p-6
    Key: XIPRSXSGWQCSHH-UHFFFAOYSA-H
  • [Na+].o=c(-c(=o)o1)o[Fe-3]123(oc(-c(=o)o2)=o)oc(-c(=o)o3)=o.[Na+].[Na+]
Properties
C6FeNa3O12
Molar mass 388.868 g·mol−1
Density 1.97 g/cm3 at 17 °C
32.5pts per 100pts solvent, cold water, 182pts per 100pts, boiling water [1]
Structure
octahedral
0 D
Hazards
Main hazards Corrosive. Eye, respiratory and skin irritant.
GHS pictograms GHS-pictogram-exclam.svg
GHS Signal word Warning
H302, H312
P264, P270, P280, P301+312, P302+352, P312, P322, P330, P363, P501
Related compounds
Other anions
Potassium ferrioxalate
Related compounds
Iron(II) oxalate
Iron(III) oxalate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Sodium ferrioxalate is a chemical compound with the formula Na
3
Fe(C
2
O
4
)
3
. It is also called sodium oxalatoferrate or sodium trisoxalatoferrate.

The compound is a salt consisting of ferrioxalate anions, [Fe(C
2
O
4
)
3
]3−
, and sodium cations Na+. The anion is a transition metal complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate ions C
2
O2−
4
anions acting as ligands.

The ferrioxalate anion is sensitive to light and higher-energy electromagnetic radiation, which causes the decomposition of one oxalate to carbon dioxide CO
2
and reduction of the iron(III) atom to iron(II).

Properties

Solubility

This compound is very soluble in hot water, (182 parts per 100 parts solvent by mass), but a lot less soluble in cold water, (32 parts per 100 parts solvent), about the solubility of sodium chloride. It is not appreciably soluble in ethanol or ethanol water mixtures which are more than 50% ethanol by mass. It is somewhat more soluble in water than the corresponding potassium salt.[ citation needed ]

Preparation

Sodium trisoxalatoferrate crystals Na3FeOx3 01.JPG#filelinks
Sodium trisoxalatoferrate crystals

Sodium ferrioxalate can be obtained by mixing solutions of sodium oxalate and ferric oxalate, and waiting a few hours for the brown colour of the ferric oxalate to be replaced with the green colour of the complex anion.

3 Na
2
C
2
O
4
+ Fe
2
(C
2
O
4
)
3
→ 2 Na
3
[Fe(C
2
O
4
)
3
]

The equilibrium is attained only slowly at room temperature. The product can then be crystallized by evaporating the solution at just below boiling until small crystals appear, then allowing it to cool. The product may also be precipitated by adding methanol or ethanol to the solution.

Some decomposition of the ferric oxalate may occur during the process, resulting in the canary-yellow insoluble iron(II) oxalate. Small amounts of hydrogen peroxide H
2
O
2
may be added to keep the iron in the 3+ oxidation state.

See also

A number of other iron oxalates are known

Related Research Articles

Carboxylic acid Organic compound

A carboxylic acid is an organic acid that contains a carboxyl group (C(=O)OH) attached to an R-group. The general formula of a carboxylic acid is R−COOH or R−CO2H, with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.

Metallocene

A metallocene is a compound typically consisting of two cyclopentadienyl anions (C
5
H
5
, abbreviated Cp) bound to a metal center (M) in the oxidation state II, with the resulting general formula (C5H5)2M. Closely related to the metallocenes are the metallocene derivatives, e.g. titanocene dichloride, vanadocene dichloride. Certain metallocenes and their derivatives exhibit catalytic properties, although metallocenes are rarely used industrially. Cationic group 4 metallocene derivatives related to [Cp2ZrCH3]+ catalyze olefin polymerization.

Oxide Chemical compound with at least one oxygen atom

An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. Metal oxides thus typically contain an anion of oxygen in the oxidation state of −2. Most of the Earth's crust consists of solid oxides, the result of elements being oxidized by the oxygen in air or in water. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 (called a passivation layer) that protects the foil from further corrosion. Certain elements can form multiple oxides, differing in the amounts of the element combining with the oxygen. Examples are carbon, iron, nitrogen (see nitrogen oxide), silicon, titanium, and aluminium. In such cases the oxides are distinguished by specifying the numbers of atoms involved, as in carbon monoxide and carbon dioxide, or by specifying the element's oxidation number, as in iron(II) oxide and iron(III) oxide.

In chemistry, a salt is a chemical compound consisting of an ionic assembly of cations and anions. Salts are composed of related numbers of cations and anions so that the product is electrically neutral. These component ions can be inorganic, such as chloride (Cl), or organic, such as acetate ; and can be monatomic, such as fluoride (F) or polyatomic, such as sulfate.

Sodium hydroxide Chemical compound with formula NaOH

Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+
and hydroxide anions OH
.

Iron(III)

In chemistry, iron(III) refers to the element iron in its +3 oxidation state. In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe3+.

Potassium hydroxide Inorganic compound with the formula KOH

Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.

Oxalate Any derivative of oxalic acid; chemical compound containing oxalate moiety

Oxalate (IUPAC: ethanedioate) is a compound found in some foods, which when consumed exits the body through the urine. Excess consumption has been linked to gout and kidney stones. Many metal ions form insoluble precipitates with oxalate, a prominent example being calcium oxalate, the primary constituent of the most common kind of kidney stones. Several plant foods such as the root and/or leaves of spinach, rhubarb, and buckwheat are high in oxalic acid and can contribute to the formation of kidney stones in some individuals. Chemically, oxalate is a dianion with the formula C
2
O2−
4
, also written (COO)2−
2
. Either name is often used for derivatives, such as salts of oxalic acid, for example sodium oxalate Na2C2O4, or dimethyl oxalate ((CH3)2C2O4). Oxalate also forms coordination compounds where it is sometimes abbreviated as ox.

Ferrate(VI) Ion

Ferrate(VI) is the inorganic anion with the chemical formula [FeO4]2−. It is photosensitive, contributes a pale violet colour to compounds and solutions containing it and is one of the strongest water-stable oxidizing species known. Although it is classified as a weak base, concentrated solutions containing ferrate(VI) are corrosive and attack the skin and are only stable at high pH.

In chemical nomenclature, the IUPAC nomenclature of inorganic chemistry is a systematic method of naming inorganic chemical compounds, as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in Nomenclature of Inorganic Chemistry. Ideally, every inorganic compound should have a name from which an unambiguous formula can be determined. There is also an IUPAC nomenclature of organic chemistry.

Iron(III) nitrate Chemical compound

Iron(III) nitrate, or ferric nitrate, is the chemical compound with the formula Fe(NO3)3.

Potassium ferrioxalate Chemical compound

Potassium ferrioxalate, also known as potassium trisoxalatoferrate or potassium tris(oxalato)ferrate(III) is a chemical compound with the formula K
3
[Fe(C
2
O
4
)
3
]. It often occurs as the trihydrate K
3
[Fe(C
2
O
4
)
3
]·3H2O
. Both are crystalline compounds, lime green in colour.

Oxygen compounds

The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: −12 (superoxides), −13 (ozonides), 0, +12 (dioxygenyl), +1, and +2.

Barium ferrate Chemical compound

Barium ferrate is the chemical compound of formula BaFeO4. This is a rare compound containing iron in the +6 oxidation state. The ferrate(VI) ion has two unpaired electrons, making it paramagnetic. It is isostructural with BaSO4, and contains the tetrahedral [FeO4]2− anion.

Iron(II) The element iron in its +2 oxidation state

In chemistry, iron(II) refers to the element iron in its +2 oxidation state. In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe2+.

Iron(II) oxalate Chemical compound

Ferrous oxalate, or iron(II) oxalate, is an inorganic compound with the formula FeC2O4 • xH2O where x is typically 2. These are orange compounds, poorly soluble in water.

Ferric oxalate Chemical compound

Ferric oxalate, also known as iron(III) oxalate, is a chemical compound composed of ferric ions and oxalate ligands; it may also be regarded as the ferric salt of oxalic acid. The anhydrous material is pale yellow; however, it may be hydrated to form several hydrates, such as potassium ferrioxalate, or Fe
2
(C
2
O
4
)
3
 • 6H2O, which is bright green in colour.

Metal halides

Metal halides are compounds between metals and halogens. Some, such as sodium chloride are ionic, while others are covalently bonded. Covalently bonded metal halides may be discrete molecules, such as uranium hexafluoride, or they may form polymeric structures, such as palladium chloride.

Potassium ferrooxalate, also known as potassium bisoxalatoferrate(II), is a salt with the formula K
2
[Fe(C
2
O
4
)
2
], sometimes abbreviated K
2
FeOx
2
. The ferrooxalate anion [Fe(C
2
O
4
)
2
]2−
is a transition metal complex, consisting of an atom of iron in the +2 oxidation state bound to two bidentate oxalate ions C
2
O2−
4
. The anion charge is balanced by two cations of potassium K+
.

Ferrioxalate Ion

Ferrioxalate or trisoxalatoferrate(III) is a trivalent anion with formula [Fe(C
2
O
4
)
3
]3−
. It is a transition metal complex consisting of an iron atom in the +3 oxidation state and three bidentate oxalate ions C
2
O2−
4
anions acting as ligands.

References

  1. Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. B-149. ISBN   0-8493-0462-8.