✔ 最佳答案
no, supposedly there's no direct reactions.
there's double salt formed by iron(II) and ammonium -- Mohr's salt, ammonium iron(II) sulfate (NH4)2Fe(SO4)2.6H2O -- which is a convenient source of more stable iron(II). however, it's NOT directly produced by mixing two respective solutions.
2011-03-26 17:05:59 補充：
according to some data, the (molar) solubility of either salt decreases after reaction.
that is, say, both saturated salt solution has concentration of 1M; after reaction, solubility of Mohr's salt is 0.8M, leading to presence of excessive Mohr's salt not dissolved.
2011-03-26 17:07:33 補充：
hydrate analysis is not always very accurate; plus or minus one water should be acceptable, taking experimental error into account.
