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Ammonium iron(II) sulfate, or Mohr's Salt (named after a German scientist Karl Friedrich Mohr) , is the inorganic compound with the formula (NH4)2SO4FeSO4.6H2O.
A 2155 (OTTO) Ammonium ferrous sulphate, 98% Cas 7783-85-9 - used in the Fricke's dosemeter to measure h igh doses of gamma rays.