Question

1. Calculations Given the following data, determine the % by mass of oxalate (C₂O₄^2-) in a sample of an iron oxalate complex with the general formula K_z[Fe_x(C₂O₄)_y].wH₂O.

The reaction between oxalate and permanganate is as follows:

6H⁺ + 5(COOH)₂ + 2MnO₄^- → 10CO₂ + 2Mn²⁺ + 8H₂O

m(iron oxalate complex) used for titration = 0.100 g

C(KMnO₄) standard solution = 0.0200 M

M(C₂O₄^2-) = 88.02 g mol^-1

Titre volume = 10.18 mL

Enter your answer to 3 significant figures.

2. Given the following data, determine the % by mass of Iron (III) (Fe³⁺) in a sample of an iron oxalate complex with the general formula K_z[Fe_x(C₂O₄)_y].wH₂O.

m(iron oxalate complex) used for stock sample = 0.0100 g

V_total (stock sample solution) = 25.00 mL

V_aliquot (stock sample solution) = 1.00 mL

V_total (diluted sample solution) = 25.00 mL

C_dil(Fe³⁺) = 1.667 mg L^-1 (from calibration curve)

Enter your answer to 3 significant figures.

Answer 1