Silverado7 - 26-10-2008 at 15:59
Since there isn't a lot of action going on in this discussion board, I would like to help in doing the opposite. I know that it's better not to say
anything if it's a waste of time, but in this case, I think it's a rather intersting topic to discuss. Heating ammonium iron sulfate. Online or in the
books I couldn't find anything useful in my research. My first idea was that it is heated to give off something corresponding to sulfur trioxide, or
maybe ammonia, I'm not the slightest bit sure. So, any thoughts?
Formatik - 26-10-2008 at 20:54
You'll most likley get sulfur oxides, ammonia, and iron oxides as products of decomposition.
Silverado7 - 27-10-2008 at 11:36
Since the vapor from the heating the reactant will be caught in water, it would make.. well, I'm not sure. If any sulfur oxide, it would be trioxide.
There's only one ammonia, and the iron oxides I'm not sure. Where would it get the oxygen if it did? SO the sulfur trioxide would combine with the
water to form sulfuric acid. The ammonia would combine with water to form ammonia liquid. I would be ammonium sulfate solution. However, I'm not sure
what the iron in ammonium iron sulfate's composition would do. The question is, if you heat iron, what happens. With that data, we can solve this
equation. Oh yeah, it doesn't really matter that the ammonium iron sulfate is not anhydrous because it will turn anhydrous when heated as a first
stage. That doesn't matter now, though.
Formatik - 1-11-2008 at 09:32
Heating ammonium iron(III) sulfate converts its pink white color to yellow, and Fe2(SO4)3, then later Fe2O3. Its decomposition occurs at about 420 to
430º, at 480 to 490º conversion to Fe2(SO4)3 is complete, between 640 to 710º is the conversion to Fe2O3 according to Sci. Rep. Tôhoku 4 [1915]
231; Bl. chem. Soc. Japan 3 [1928] 122.
That being the case, it looks like the NH3 volatilizes off from the molecule at first. Then what you are left with is ferric sulfate, aka iron (III)
sulfate, Fe2(SO4)3. This decomposes by further heat to give SO3, Fe2O3. Likely ammonium iron (II) sulfate follows a similar pattern of decomposition.