Question

A standard iodate solution is prepared at 22.0 °C by dissolving 0.9123 g (uncorrected mass) of KIO3 with deionized water in a 499.92 mL volumetric flask.To standardize the Na2S2O3 solution, a 10.005 mL aliquot of the KIO3 solution is acidified, treated with excess KI, an d titrated with Na2S2O3, requiring 22.05 mL to reach the end point. Finally, a 10.005 mL aliquot of unknown Cu solution is reduced with excess KI. The liberated iodine requires 31.46 mL of Na2S2O3 solution to reach the end point. Calculate the unknown Cu concentration in g/L.