A 3.026-g portion of a copper(II) salt was dissolved in a 250-mL volumetric flask. A 50.0 mL aliquot was analyzed by adding 1 g of KI and titrating the liberated iodine with 23.33 mL of 0.046 68 M Na2S2O3. Find the weight percent of Cu in the salt. Should starch indicator be added to this titration at the beginning or just before the end point?