Copperas

V. Shorrocks, Ese of Copperas a Micronutrient for Crops, Parti, Planning Study, INCRA, New York, July 1984. 

Chemical Designations - Synonyms Copperas, Green vitriol, Iron(ous) sulfate. Iron vitriol Chemical Formula FeS04 7H20. 

Eisenvitriol, m. iron vitriol (hydrous ferrous sulfate, copperas). — roter —, red vitriol, botryogen. 

Ferrous sulfate (copperas), (FeS04) 7H20 This is similar to ferric sulfate. The optimum coagulation pH level for these last two iron salts is typically 8.0 to 9.0 but may need to be lowered. 

Copperas [green vitriol or ferrous sulfate (FeS04 7H20)] was also employed as an external coagulant (at pH values of approximately 7.7). It forms a turbid precipitate, and when oxygen is present (as is usual), a slimy precipitate of ferrous hydroxide also may form in addition to ferric hydroxide ... 

The most important synthetic routes to iron oxide pigments involve either thermal decomposition or aqueous precipitation processes. A method of major importance for the manufacture of a-Fe203, for example, involves the thermal decomposition in air of FeS04-7H20 (copperas) at temperatures between 500 °C and 750 °C. The principal method of manufacture of the yellow a-FeO(OH) involves the oxidative hydrolysis of Fe(n) solutions, for example in the process represented by reaction (1). 

The name of compounds whose molecules contain three or more elements, usually including oxygen, ends in the suffix ate. Thus the chemical name for limestone, whose chemical formula is CaC03, is calcium carbonate. That of green vitriol, also known as copperas, whose formula is FeS04, is iron sulfate. The names and formulas of some chemical compounds related to archaeological studies are listed in Table 7. 

Chemical and other names Copper Cupric sulfate, blue vitriol, cupric sulfate, Roman vitriol, Salzburg vitriol, blue copperas, copper (II) sulfate)... 

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