Question

Using the Mole: Empirical Formulas, Molecular Formulas, % Composition 2. Find the empirical formulas for the following compounds: C. 72.4% Fe, 27.6%O

Answer 1

Step-by-step explanation

Given:

% composition: 72.4% Fe, 27.6% O

What to find:

The empirical formula for the compound.

Step-by-step solution:

Step 1: Start by converting the percent composition to grams by using a

100 g sample of the compound.

72.4% Fe ----> (72.4/100) x 100 g = 72.4 g

27.6% O -----> (27.6/100) x 100 g = 27.6 g

Step 2: Use the molar masses of the two elements to convert the masses to moles.

From the periodic table, the molar masses of Fe = 55.845 g/mol and O = 15.999 g/mol

For Fe: (72.4 g/55.845 g/mol) = 1.2964 mol45

For O: (27.6 g/15.999 g/mol) =