Chemistry
posted by Jane .
How many milliliters of a 3.85 M solution of Fe2+ are needed to titrate 250.0 mL of a 0.125 M Cro4 2 solution?
H + CrO4 2 + Fe2+ yields to Fe3+ + Cr2O3 + H2) (not balanced)

Balance the equation.
Calculate moles CrO4^2 used. That is moles = M x L = ?
Convert moles CrO4^2 to moles Fe^2+ using the coefficients in the balanced equation.
Then M Fe^2+ = moles Fe^2+/L Fe^2+
Solve for L and convert to mL.