A sample contained a mixture of ZnS and HgS. The amount of ZnS was determined by reacting 11.06 g of the sample with an excess of HCl to release H2S from each compound; ZnS(s) + 2 HCl(aq) ® ZnCl2 + H2S(g) HgS(s) + 2 HCl(aq) ® HgCl2 + H2S(g) If the sample reacted completely and produced 2143 mL of hydrogen sulfide at 29.06 °C and 699.2 mm Hg, what was the mass percentage of ZnS in the mixture?