# Chem

posted by .

In lab, the ratio of moles C2O4^2-/Fe^3+ was 0.0063 to 0.0017, which is 3.7 . However, I am having a hard time deducing the formula and charge on complex ion. The unbalanced formula I had to use was:

Fe^3+(aq) + C2O4^2+(aq) = Fex(C2O4)y^(3x-2y)

Since the compound's name is Iron(III) salicylate, what is x and y?

• Chem -

I don't get the connection between the oxalate ion (C2O4^-2) and the name salicylate.

• Chem -

Sorry, forget the name of compound. How do I find x and y?

• Chem -

From your data I would do this but it's a stretch.
0.0063 = C2O4^-2
0.0017 = Fe^+3

Divide both by the smaller number which gives you 1 mole Fe to 3.7 moles C2O4^-2. Round the 3.7 to the nearest whole number (4.0) (that's the stretch) so that would make it Fe(C2O4)4 (x=1 and y = 4) so the charge on the ion you have is -5. I think the correct formula for the complex is
Fe(C2O4)3^-3

• Chem -

Is it supposed to be Fe(C2O4)4^-5?

Why Fe(C2O4)3^-3?

• Chem -

You need to re-read my response. Your data shows it to be Fe(C2O4)4^-5 but the correct formula of the complex, I believe, is Fe(C2O4)3^-3.