Question

If 350.0 grams of Cr2O3 are reacted with 235.0 grams of elemental silicon, 213.2 grams of chromium metal are recovered. What is the percent yield?

Answer 1

We calculate for the amount of chromium metal in the reactant by,
= 350 x (mass of Cr2/mass of Cr2O3)
= 350 x (104/152)
= 239.47 grams
The amount of Cr metal in the product is only 213.2 grams. Thus, the percent yield.
percent yield = (213.2 grams/239.47) x 100%
= 89%