[ridic]

I was given a standard Fe+3 solution equal to 0.0500 mg Fe+3/mL. I took 2 mL of this solution and put in a 50 mL volumetric flask. I added 1 mL of 1 M NH4C2H3O2, 1 mL of 10% hydroxylamine hydrochloride, 10 mL of 0.3% o-phenathroline, and diluted it to a total volume of 50 mL. What is the concentration of my Fe+3 at the end of this?

[english]

2 mL of 0.0500 mg/mL iron(III) is how many milligrams?  You diluted this to a total volume of 50 mL.

Your total volume is all that matters.  You're determining the concentration with respect to iron(III), not the other species present.

[Borek]

First: english is right.

Second: you have a lot of complexing agents in the solution. Hopefully the question doesn't ask about free Fe³⁺...