Compounds of carbon are defined as chemical substances containing carbon. More compounds of carbon exist than any other chemical element except for hydrogen. Organic carbon compounds are far more numerous than inorganic carbon compounds. In general bonds of carbon with other elements are covalent bonds. Carbon is tetravalent but carbon free radicals and carbenes occur as short-lived intermediates. Ions of carbon are carbocations and carbanions are also short-lived. An important carbon property is catenation as the ability to form long carbon chains and rings.
Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe2O3 is the main source of iron for the steel industry. Fe2O3 is readily attacked by acids. Iron(III) oxide is often called rust, and to some extent this label is useful, because rust shares several properties and has a similar composition. To a chemist, rust is considered an ill-defined material, described as hydrated ferric oxide.
Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalate with the chemical formula CaC2O4·(H2O)x, where x varies from 0 to 3. All forms are colorless or white. The monohydrate occurs naturally as the mineral whewellite, forming envelope-shaped crystals, known in plants as raphides. The rarer dihydrate (mineral: weddellite) and trihydrate (mineral: caoxite) are also recognized. Calcium oxalates are a major constituent of human kidney stones. Calcium oxalate is also found in beerstone, a scale that forms on containers used in breweries.
Iron(III) chloride (FeCl
3), also called ferric chloride, is an industrial scale commodity chemical compound with iron in the +3 oxidation state. The compound also exist as a hexahydrate with the formula trans-[Fe(H
2O)
4Cl
2]Cl · 2H2O normally written as FeCl
3 · 6H
2O. The anhydrous compound is a crytalline solid with a melting point of 307.6 °C. The color depends on the viewing angle: by reflected light the crystals appear dark green, but by transmitted light they appear purple-red. The hexahydrate has a melting point of 37 °C and appears orange-brown in color. In nature, iron(III) chloride is known as the mineral molysite, but it is rare and mainly found from some fumaroles. It is however an industrial scale commodity.
Iron(II) oxide or ferrous oxide is the inorganic compound with the formula FeO. Its mineral form is known as wüstite. One of several iron oxides, it is a black-colored powder that is sometimes confused with rust, the latter of which consists of hydrated iron(III) oxide. Iron(II) oxide also refers to a family of related non-stoichiometric compounds, which are typically iron deficient with compositions ranging from Fe0.84O to Fe0.95O.
Oxalic acid is an organic compound with the formula C2H2O4. It is a colorless crystalline solid that forms a colorless solution in water. Its condensed formula is HOOCCOOH, reflecting its classification as the simplest dicarboxylic acid.
Oxalate (IUPAC: ethanedioate) is the dianion with the formula C
2O2−
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.
Sodium oxalate, or disodium oxalate, is the sodium salt of oxalic acid with the formula Na2C2O4. It is a white, crystalline, odorless solid, that decomposes above 290 °C.
Zhemchuzhnikovite is an oxalate mineral of organic origin; formula NaMg(FeAl)C2O4·8H2O. It forms smokey green crystals with a vitreous lustre and is found in Russian coal mines. It is named after Yury Zhemchuzhnikov (1885–1957), a Russian clay mineralogist.
Barium oxalate (BaC2O4), a barium salt of oxalic acid, is a white odorless powder that is sometimes used as a green pyrotechnic colorant generally in specialized pyrotechnic compositions containing magnesium.
Potassium ferrioxalate is a chemical compound with the formula K
3[Fe(C
2O
4)
3]. It often occurs as the trihydrate K
3[Fe(C
2O
4)
3] · 3H2O. Both are crystalline compounds, lime green in colour., also known as potassium trisoxalatoferrate or potassium tris(oxalato)ferrate(III).
Permanganometry is one of the techniques used in quantitative analysis in chemistry. It is a redox titration and involves the use of permanganates and is used to measure the amount of analyte present in unknown chemical samples.
It involves two steps, namely the titration of the analyte with potassium permanganate solution and then the standardization of potassium permanganate solution with standard sodium oxalate solution. The titration involves volumetric manipulations to prepare the analyte solutions.
Hydrogenoxalate or hydrogen oxalate is an anion with chemical formula HC
2O−
4 or HO
2C–CO−
2, derived from oxalic acid by the loss of a single proton; or, alternatively, from the oxalate anion C
2O2−
4 by addition of a proton.
Ferrous oxalate, or iron(II) oxalate, is a inorganic compound with the formula FeC2O4 · xH2O where x is typically 2. These are orange compounds, poorly soluble in water.
Sodium ferrioxalate is a chemical compound with the formula Na
3Fe(C
2O
4)
3. It is also called sodium oxalatoferrate or sodium trisoxalatoferrate.
Strontium oxalate is a compound with the chemical formula SrC2O4. Strontium oxalate can exist either in a hydrated form (SrC2O4•nH2O) or as the acidic salt of strontium oxalate (SrC2O4•mH2C2O4•nH2O).
Magnesium oxalate is an inorganic compound comprising a magnesium cation with a 2+ charge bonded to an oxalate anion. It has the chemical formula MgC2O4. Magnesium oxalate is a white solid that comes in two forms: an anhydrous form and a dihydrate form where two water molecules are complexed with the structure. Both forms are practically insoluble in water and are insoluble in organic solutions.
Potassium ferrooxalate, also known as potassium bisoxalatoferrate(II), is a salt with the formula K
2[Fe(C
2O
4)
2], sometimes abbreviated K
2FeOx
2. The ferrooxalate anion [Fe(C
2O
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
2O2−
4. The anion charge is balanced by two cations of potassium K+
.
Ferrioxalate or trisoxalatoferrate(III) is a trivalent anion with formula [Fe(C
2O
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
2O2−
4 anions acting as ligands.
