Invariably there is among these a formula for ferrous oxalate developer.
That a minute quantity of iron is dissolved by the carbonic acid contained in the water, ferrous bicarbonate being formed.
Calculate the value of the ferrous salt in terms of bichromate.
To obtain these the gold is first precipitated from the solution by ferrous chloride, all the other metals by iron turnings.
Fig. 121 shows us, also, what are the conditions under which the reduction of ferric to ferrous oxide by carbon can occur.
Ferrous oxide is obtained when ferric oxide is reduced in hydrogen at 300 as a black pyrophoric powder.
The solution, in common with those of most ferrous salts, absorbs nitric oxide with the formation of a brownish solution.
Another black amorphous form results when ferrous salts are precipitated by ammonium sulphide.
Ferrous iodide, FeI2, is obtained as a grey crystalline mass by the direct union of its components.
Ferrous sulphate forms double salts with the alkaline sulphates.