ferrous oxide

Chem.: FoO. Protoxide of iron, obtained as a black powder by heating iron in carbon dioxide, Fe+CO2=FOO+CO. It takes fire when heated in the air, forming ferric oxide. The hydrate of ferrous oxide, Fe(OH)2, ferrous hydrate, is obtained as a white precipitate when a solution of a ferrous salt is mixed with a solution of caustic potash, both perfectly free from air. If boiled in a ve el free from oxygen it loses its water of hydration, becoming black. Ferrous hydrate rapidly absorbs oxygen from the air, the color changing from white to green and then to red brown, owing to the formation of ferric hydrate. Ferrous hydrate is slightly soluble in a solution of ammonia. ferrous sulphate, s. 1. Chem. FeSO4.7H2O. Pro to sulphate of iron, green vitriol, iron vitriol, copperas, sulphate of iron. Ferrous sulphate is obtained pure by di olving iron wire in pure dilute sulphuric acid, also when ferrous sulphide is acted upon with dilute sulphuric acid in the preparation of sulphide of hydrogen, H2S. On evaporating the ferrous sul phate separates out in transparent and bluish-green Phomboidal crystals, which effloresce in dry air; in moist air they become coated with a brown crust of ferric sulphate. Ferrous sulphate is insoluble in alcohol, and soluble in twice its weight of cold water. The salt loses six molecules of water at 100° and retains the other molecule till it is heated to 300°. At red heat it is decomposed, yielding Nordhausen sulphuric acid and ferric oxide. A solution of ferrous sulphate gradually absorbs oxygen when exposed to the air, but can be kept by placing iron wire in the solution. It absorbs dioxide and trioxide of nitrogen, forming a dark brown liquid which rapidly absorbs oxygen. Ferrous sulphate forms double salts with the alkaline sulphates, as FeSO, K.SO+6H2O. These salts are used to determine the strength of permanganate and bichromate solutions employed in volumetrical analysis. Ferrous sulphate is used as a black dye in combination with vegetable astringent matters. 1811 Large quantities of ferrous sulphate are obtained by exposing to the action of air and moisture iron pyrites, FeS2, which is decomposed into FeSO4 and H2SO4; the latter acting on the clay forms aluminium sulphate. fertilely 2. To carry or transport over a river, strait, of other narrow water, in a boat, barge, . "The rugged Charon fainted, And asked a navy rather than a boat To ferry over the sad world that came." Ben Jonson: Cat i line, i. 1. 2. Pharm.: Ferrous sulphate, Ferri sulphas , used in the preparation of Mist . ferri comp. For- *B. In trans.: To pa or be transported in e sulphate of iron, Ferri sulphas granulata , is prepared by pouring a hot solution of ferrous sulphate into rectified spirit, and stirring the mixture, so that the salt shall separate in minute granular crys tals.