Really need help on figuring out the formula for Iron Complex.
The question was:
4.0 g of ferrous ammonium sulphate, FeS04(NH4)2*SO4*6H20, is used. The oxalate is in excess, calculate the theoretical yield of the iron complex.
I got the moles of ferrous ammonium sulfate but I am stuck on how to figure out the balanced equation and the formula for the iron complex.
Wouldn't it be just FeC2O4? Since Fe has a 2+ charge and C2O4 has a 2- charge?
I've looked around in the internet and their answer was this: [Fe(C2O4)3]3-
I don't understand.
This problem has been posted a number of times with varying parts of what I suppose was the initial entire question. Here is a way to get to the site; I can't copy it to this page. Click on the PDF file of Chemistry 112.
http://www.google.com/search?q=potassium+hexaoxalatoferrate%28III%29&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
To find the balanced equation for the formation of the iron complex in this reaction, you need to consider the reactants and products involved.
The reactants are ferrous ammonium sulfate (FeS04(NH4)2*SO4*6H20) and an excess of oxalate (C2O4^2-). The oxalate will react with the iron ions in the ferrous ammonium sulfate to form the iron complex. The products will be the iron complex and any remaining reactants.
The balanced equation for the reaction can be represented as follows:
3 [Fe(NH4)2(SO4)2*6H2O] + 3 [C2O4^2-] → [Fe(C2O4)3]3- + 6 NH4+ + 2 SO4^2- + 18 H2O
Here, the coefficient of 3 in front of ferrous ammonium sulfate indicates that three moles of ferrous ammonium sulfate react with three moles of oxalate to form one mole of the iron complex, [Fe(C2O4)3]3-. The resulting complex has a charge of 3-.
Therefore, the correct formula for the iron complex is indeed [Fe(C2O4)3]3-, rather than just FeC2O4. The complex contains three oxalate ions (C2O4^2-) to balance the charge of the iron ion (Fe^3+).
To calculate the theoretical yield of the iron complex, you need to convert the given mass of ferrous ammonium sulfate (4.0 g) to moles, taking into account its molar mass. Then, using the stoichiometry of the balanced equation, you can determine the moles and mass of the iron complex that would be formed if the reaction goes to completion.