Iron(II) sulfide reacts with hydrochloric acid according to the reaction:
FeS(s)+2HCl(aq)→FeCl2(s)+H2S(g)
A reaction mixture initially contains 0.228 molFeSand 0.654 mol HCl.
Once the reaction has occurred as completely as possible, what amount (in moles) of the excess reactant is left?