Answer to Question #192335 in Chemistry for Torrie Alexis Scha

Question

If steel wool (iron) is heated until it glows and is placed in a bottle containing pure oxygen, the iron reacts to produce iron (III) oxide.

4 Fe + 3 O2 → 2 Fe2O3 

 

a) If 1.25 g of iron is heated and placed in a bottle containing 0.500 grams of oxygen gas how many grams of iron (III) oxide should be produced?

Answer 1

M (Fe) = 55.9 g/mol

M (O₂) = 32 g/mol

M (Fe₂O₃) = 159.7 g/mol

n = m / M

n (Fe) = 1.25 / 55.9 = 0.022 mol

n (O₂) = 0.5 / 32 = 0.016 mol

According to the equation, n (Fe₂O₃) = 2/4 x n (Fe) = 2/3 x n (O₂).

2/4 x n (Fe) = 0.017 mol

2/3 x n (O₂) = 0.01 mol

It appears to be that O₂ is the limiting reagent. Therefore, Fe₂O₃ calculations will be based on it.

m (Fe₂O₃) = n x M = 0.01 x 159.7 = 1.6 g