An iron ore was found to contain 92.0% pyrite (fool’s gold). Pyrite has the formula FeS2 and is 46.5% iron. How many grams of iron are there in 59.1 grams of iron ore?
To find the amount of pyrite you need to multiply the total mass of the ore by the percent that is pyrite.
59.1g * .92 = 54.372g
Multiply the grams of pyrite by the percent of pyrite that is iron to get the number of grams of iron in the ore.
54.372g * .465 = 25.28298g
Adjust for significant figures.