Hydrogen Sulphide

Statement-1: In neutral solution, there is partial precipitation of zinc sulphide by hydrogen sulphide gas. Statement-2: The complete precipitation of zinc sulphide takes place by hydrogen sulphide gas when alkali metal acetate is added to the solution.

A mineral containing iron(II) sulphide but no other sulphides is treated with excess hydrochloride acid to produce hydrogen sulphide. . If a 3.15g sample of the mineral yields 448 mL of hydrogen sulphide gas (measured at 0^(@)C and 760 mm Hg), what is the mass percentage of iron (II) sulphide inthe sample?