A 1.206 gram sample containing an unknown amount of arsenic trichloride and the rest inerts was dissolved into a NaHCO3 and HCl aqueous solution. To this solution was added 1.870 grams of Kl and 50 ml of a 0.00844 M KlO3 solution. The excess I3 (-) was titrated with 50 ml of a 0.02 M Na2S2O3 solution ,What was the mass percent of arsenic trichoride in the original sample?