The Amount of Iron in a Sample Can Be Determined $\rarr$

Multiple Choice

The amount of iron in a sample can be determined by a titration using dichromate ion, Cr₂O₇^2-, in acidic solution. The iron is first converted to Fe²⁺, which is then titrated by the dichromate ion. The reaction is:
6 Fe²⁺(aq) + Cr₂O₇^2-(aq) + 14 H⁺ $\rarr$ 6 Fe³⁺(aq) + 2 Cr³⁺(aq) + 7 H₂O How many grams of iron are present in a sample if it required 42.7 mL of 0.0180 M Na₂Cr₂O₇(aq) solution for the titration described by the redox equation above?

A) 0.043 g
B) 0.258 g
C) 3.61 g
D) 7.07 g
E) 7.15 g