An iron ore sample contains plus other impurities. A 729-g sample of impure iron ore is heated with excess carbon, producing 277 g of pure iron by the following reaction: What is the mass percent of in the impure iron ore sample?

Explanation:

m(total) = 729 g

m(pure) = 277 g

Mass of impure iron ore sample:

W(impure) - mass percent

W(impure) = m(total) - m(pure) / m(total) = 729 g - 277 g / 729 g

= 0,62 ⇒ 62%

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