A mixture containing iron(III) sulfide and iron(III) chloride isreacted with hydrochloric acid.
Fe2S3 + 6HCL --> 2FeCl3 + 3H2S
The iron(III) chloride does not react with hydrochloric acid. When the 5.000g mixture is reacted with excess hydrochloric acid,420.25 mL of hydrogen sulfide gas is collected, measured at18.6 degree Celsius and an atmospheric pressure of 751.2 torr.
The number of moles of hydrogen sulfide gas collected is 0.01668 moles. Determine the percentage of iron(III) sulfide in the original mixture.