Ammonium iron(II) sulfate, or Mohr's Salt (named after a German scientist Karl Friedrich Mohr) , is the inorganic compound with the formula (NH4)2Fe(SO4)2·6H2O. Containing two different cations, Fe2+ and NH4+, it is classified as a double salt of ferrous sulfate and ammonium sulfate. It is a common laboratory reagent. Like the other ferrous sulfate salts, ferrous ammonium sulfate dissolves in water to give the aquo complex [Fe(H2O)6]2+, which has octahedral molecular geometry.
This compound is a member of a group of double sulfates called Schönites or Tutton's salts. which form monoclinic crystals...