Iron (ii) sulfide reacts with hydrochloric acid according to the reaction: fes(s) + 2 hcl(aq)→ fecl2(s) + h2s(g) a reaction mixture initially contains 0.223 mol fes and 0.652 mol hcl. once the reaction has occurred as completely as possible, what amount (in moles) of the excess reactant is left?