Exercise 54. Ferrous Ammonium Sulfate Mohrs Salt

EXERCISE 54. FERROUS AMMONIUM SULFATE (MOHR S SALT), (NHihSOcFeSOvBHaO 

Dissolve 100 g. of commercial ferrous sulfate (copperas) in 400 cc. of hot water to which has been added 1 or 2 cc. of sulfuric acid and then add an equimolecular weight of ammonium sulfate, remembering that the formula for ferrous sulfate is FeS04-7H20. It is well to add a bright iron nail and keep the solution hot for a time to reduce any ferric sulfate which may be present. Bring 

The Preparation of Alums.—Since aluminum sulfate is a commercial chemical, the aluminum alums can be prepared by crystallizing the salt along with the double molecular weight of an alkali sulfate. Chromium and ferric sulfates are not well crystallized and have limited uses, so that they are not readily obtained. The preparation of their alums involves the preliminary preparation of the sulfates themselves. 

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