Question

what is the empirical formula of a compound that contains only iron and oxygen and is 22.27% oxygen? answer: a feo b feo₂ c fe₂o d fe₇o₂

Explanation:

Step1: Assume 100g of compound

Mass of O = 22.27g, Mass of Fe = 100 - 22.27 = 77.73g.

Step2: Calculate moles of each element

Moles of O: $\frac{22.27\,\text{g}}{16.00\,\text{g/mol}} \approx 1.392\,\text{mol}$
Moles of Fe: $\frac{77.73\,\text{g}}{55.85\,\text{g/mol}} \approx 1.392\,\text{mol}$

Step3: Find mole ratio

Ratio of Fe:O = $\frac{1.392}{1.392} : \frac{1.392}{1.392} = 1:1$.

Answer:

A. FeO