521. Ammonium Ferrous Sulfate

Nomenclature

CAS number: 10045-89-3
Sulfuric acid iron(2+) ammonium salt (2:1:2); ammonium iron(II) sulfate; ferrous ammonium sulfate; iron(II) ammonium sulfate; Mohr's salt.
FeH8N2O8S2; mol wt 284.05.
Fe 19.66%, H 2.84%, N 9.86%, O 45.06%, S 22.58%.
(NH4)2Fe(SO4)2.

Description and references

Manuf from Fe, H2SO4 and NH3: Demmerle et al., Ind. Eng. Chem. 42, 9 (1950); from pickling waste: Brundin, US 2694657 (1954 to Ekstrand and Tholand). Toxicity study: H. F. Smyth et al., Am. Ind. Hyg. Assoc. J. 30, 470 (1969).

Derivative

Hexahydrate.

Nomenclature

CAS number: 7783-85-9
FeH8N2O8S2.6H2O; mol wt 392.14.
Fe 14.24%, H 5.14%, N 7.14%, O 57.12%, S 16.35%.

Properties

Pale blue-green crystals or crystalline powder. Slowly oxidizes and effloresces in air. d420 1.86. Soluble in water. Practically insol in alcohol. Keep well closed and protected from light. LD50 orally in rats: 3.25 g/kg (Smyth).

Use

In photography; as analytical standard; as polymerization catalyst; in dosimeters.