Here's how to calculate the moles of formula units in 5.67 g of iron(III) sulfate:

1. Determine the Formula:

* Iron(III) sulfate is Fe₂(SO₄)₃

2. Calculate the Molar Mass:

* Fe: 55.845 g/mol (x 2 = 111.69 g/mol)

* S: 32.065 g/mol (x 3 = 96.195 g/mol)

* O: 15.9994 g/mol (x 12 = 191.9928 g/mol)

* Total molar mass of Fe₂(SO₄)₃ = 399.8778 g/mol

3. Convert Grams to Moles:

* Use the molar mass as a conversion factor:

(5.67 g Fe₂(SO₄)₃) x (1 mol Fe₂(SO₄)₃ / 399.8778 g Fe₂(SO₄)₃) = 0.0142 moles Fe₂(SO₄)₃

Therefore, there are 0.0142 moles of formula units in 5.67 g of iron(III) sulfate.