In photography, unexposed silver bromide is removed from film by soaking the film in a solution of sodium thiosulfate, Na2S2O3. Silver ion forms a soluble complex with thiosulfate ion, S2O3 2-, that has the formula Ag(S2O3)2 3-, and formation of the complex causes the AgBr in the film to dissolve. The Ag(S2O3)2 3- complex has Kform= 2.0 x 10^13. How many grams of AgBr (Ksp= 5.0 x 10^-13) will dissolve in 249 mL of 1.55 M Na2S2O3?