The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 6.43-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq) is completely oxidized by 30.4 mL of a 0.120 M aqueous solution of KBrO3(aq). The unbalanced equation for the reaction is:
BrO3^-(aq) + Sb^3+(aq)---> Br^-(aq)+Sb^5+(aq)
Calculate the amount of antimony in the sample adn its percentage in ore.