The amount of I−3(aq) in a solution can be determined by titration with a solution containing a known concentration of S2O2−3(aq)

(thiosulfate ion). The determination is based on the net ionic equation

2S2O2−3(aq)+I−3(aq)⟶S4O2−6(aq)+3I−(aq)

Given that it requires 25.8 mL
of 0.220 M Na2S2O3(aq) to titrate a 20.0 mL sample of I−3(aq), calculate the molarity of I−3(aq) in the solution.