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Question

If 0.530 moles of iron (iii) oxalate are needed to make a solution, how many grams of iron (iii) oxalate must be used?

Answer 1

A critical thing is to know that Oxalate is C₂O₄^-2

To balance the charges with an iron(III), meaning Fe³⁺ we would need to use 2 irons and 3 oxalates so:

Fe₂(C₂O₄)₃

The molar mass of Fe₂(C₂O₄)₃ is calculated by:

So Fe₂(C₂O₄)₃ has a molar mass of 375.744 g/mole

That means 0.530 moles of it would have a mass of (375.744)(0.530) = 199.14432 grams but, using 3 sig figs, this would be 199 grams