Solubility ferrous carbonate

Colorless gas paramagnetic density 1.3402 g/L slightly heavier than air, air density 1.04 (air=l) liquefies at -151.8°C to a blue liquid the refractive index of the liquid 1.330 at -90°C the density of the liquid 1.269 g/mL at -150.2°C solidifies at -163.6°C to a bluish-white snow-hke solid critical temperature -94°C critical pressure 65 atm slightly soluble in water, 4.6 mL gas dissolves in 100 mL water at 20°C while 7.34 mL and 2.37 mL dissolve in the same volume of water at 0 and 60°C, respectively more soluble in alcohol than water soluble in carbon disulfide, and in ferrous sulfate solution (reacts). 

Temporary hardness. Probably because of the ease with which, these impurities may be removed, the acid carbonates of calcium and magnesium (and in some cases ferrous iron) are said to constitute temporary hardness in water. This type of hardness may be removed by boiling the water, whereupon the soluble acid carbonates are converted to the insoluble normal carbonates, which may be removed by filtration ... 

Carbonic acid acts on iron, yielding ferrous carbonate or soluble ferrous hydrogen carbonate, and evolving hydrogen,... 

The solubility of ferrous carbonate in water and in aqueous solutions of certain mineral salts under a pressure of two atmospheres of carbon dioxide is as follows —3... 

Sodium ferrothiocyanate, Na4Fe(CNS)6.12H20, is prepared by dissolving ferrous carbonate m thiocyanic acid and adding sodium thiocyanate.4 The salt crystallises m colourless tablets, which are soluble in water, as also in alcohol, yielding bright rose-coloured solutions. 

Ferrous carbonate, FeCOg, occurs in nature as a mineral, and can be obtained as a white precipitate by the action of carbonate ion on ferrous ion in the absence of dissolved oxygen. Like calcium carbonate, ferrous carbonate is soluble in acidic waters, the bicarbonate, Fe(HC03)2, being a soluble salt. Hard waters often contain ferrous or ferric ion. 

Mercuri-bis-2-amxnobenzoic acid.—From 30 grams of mercur " o-nitrobenzoate treated in the same way as the para compound, 27-5 grams of the anhydride of hydroxylnercuri-o-nitrobenzoic acid are isolated. This is then reduced with ferrous carbonate as before. The 5>roduct is pale yellow, easily soluble in acids or alkalies, and has no definite melting-point. ... 

Under well drained conditions, iron in soil, unless chelated, is insoluble and tends to be concentrated through weathering as the more soluble ions are removed. In poorly drained soils, iron is reduced to the soluble ferrous state and is either removed from the soil or precipitated as sulfide, phosphate, or carbonate minerals. Other processes, such as chelation, are also effective in mobilizing the iron in the soil profile. The bulk of secondary iron in soils is in the oxide forms. 

Antidotes can change the chemical nature of a poison by rendering it less toxic or preventing its absorption. Formaldehyde poisoning can be treated with ammonia to promote formation of hexamethylenetetramine sodium formaldehyde sulfoxylate can convert mercuric ion to the less soluble metallic mercury and sodium bicarbonate converts ferrous iron to ferrous carbonate, which is poorly absorbed. Chemical inactivation techniques seldom are used today, however, because valuable time may be lost, whereas emetics, activated charcoal, and gastric lavage are rapid and effective. The treatment of choice for ingestion of either acids or alkalis is dilution with water or milk. Similarly, bums produced by acid or alkali on the skin should be treated with copious amounts of water. 

For some non-ferrous metals (copper, lead, nickel) the attack by sulphuric acid is probably direct with the formation of sulphates. Lead sulphate is barely soluble and gives good protection. Nickel and copper sulphates are deliquescent but are gradually converted (if not leached away) into insoluble basic sulphates, e.g. Cu Cu(OH)2)3SO4, and the metals are thus protected after a period of active corrosion. For zinc and cadmium the sulphur acids probably act by dissolution of the protective basic carbonate film. This reforms, consuming metal in the process, redissolves, and so on. Zinc and cadmium sulphates are formed in polluted winter conditions whereas in the purer atmospheres of the summer the corrosion products include considerable amounts of oxide and basic carbonate. ... 

Most of the pollutants may be effectively removed by precipitation of metal hydroxides or carbonates using a reaction with lime, sodium hydroxide, or sodium carbonate. For some, improved removals are provided by the use of sodium sulfide or ferrous sulfide to precipitate the pollutants as sulfide compounds with very low solubilities. After soluble metals are precipitated as insoluble floes, one of the water-solid separators (such as dissolved air flotation, sedimentation, centrifugation, membrane filtration, and so on) can be used for floes removal.911 The effectiveness of pollutant removal by several different precipitation methods is summarized in Tables 5.15-5.17. 

Singer, Ph. C., and W. Stumm (1970), "The Solubility of Ferrous Iron in Carbonate-Bearing Waters , J. AWWA 62, 198-202. 

---