If 25.00 mL of an aqueous solution of the iodine was titrated with 0.0250 MNa2S2O3(aq), with starch as the indicator. The blue color of the starch-iodine composite disappeared when the 27.65 mL of the thiosulfate solution had been added. The titration reaction is below.
I2(aq) + 2S2O32-(aq) -> 2 I-(aq) +S4O62-(aq)
Describe the molar concentration of I2 in the original solution?