Question

An oxide of iron is found to be 77.75% iron by mass. Determine the empirical formula for this compound and name it.

Enter the formula with correct capitalization and subscripts (so "H2O" for H2O). Use all lowercase letters when typing names, no space before parentheses if parentheses are needed (so "tin(II) chloride")

Answer 1

To find the empirical formula of the compound, we need to find the ratio of iron and oxygen by mass. The empirical formula for the compound is FeO, and it is called iron(II) oxide.

Step-by-step explanation:

To determine the empirical formula of the compound, we need to find the ratio of the elements by mass. In this case, we have 77.75% iron and the remaining percentage is oxygen. Assuming we have a 100g sample, we have 77.75g of iron and 22.25g of oxygen.

To find the mole ratio, we need to convert the masses to moles. The molar mass of iron (Fe) is 55.85 g/mol and the molar mass of oxygen (O) is 16.00 g/mol. For iron, we have 77.75g / 55.85 g/mol = 1.39 mol and for oxygen, we have 22.25g / 16.00 g/mol = 1.39 mol.

Since the ratio of moles is already a whole number (1:1), the empirical formula of the compound is FeO. The compound is iron(II) oxide.