Question

How many Sulfur(S) atoms are in 15.2 g of Al2 (SO4)3 ?

Answer 1

Mass of Al₂(SO₄)₃ = 15.2 g

Molar mass of Al₂(SO₄)₃ = 342.15 g/mol

Moles of Al₂(SO₄)₃ = Mass/ Molar mass = 15.2 g/ ( 342.15 g/mol) = 0.0444 mol

1 mol of Al₂(SO₄)₃ contains 3 mol of S

so, 0.0444 mol of Al₂(SO₄)₃ contains 3*0.0444 = 0.133 mol of S

1 mol = 6.022 *10²³ atoms

So, 0.133 mol = 0.133 mol* 6.022 *10²³ atoms / 1mol = 8.03 *10²² atoms