Ammonium iron(II) sulfate

Ammonium iron(II) sulfate is an analytical reagent in titrations and colorimetric measurements to measure oxidizing substances, such as chlorine, or to measure the chemical oxygen demand in waste water. The compound is used to prepare Fe(II) standard solution for these analyses. It also is a calibration standard in magnetic measurements; a reducing agent; a catalyst for polymerization; and is used in photographic chemistry.