Question

Calculate the number of moles of aluminum, sulfur, and oxygen atoms in 9.00 moles of aluminum sulfate, Al2(SO4)3.

Express the number of moles of  Al

,  S , and  O  atoms numerically, separated by commas.

Answer 1

The formula of aluminum sulfate is Al₂(SO₄)₃

Hence, 1 mole of Al₂(SO₄)₃ has 2 moles of Al, 3 moles of S and (4 x 3) or 12 moles of O

9 moles of Al₂(SO₄)₃ x (2 moles of Al/1 mole of Al₂(SO₄)₃) = 18 moles of Al

9 moles of Al₂(SO₄)₃ x (3 moles of S/1 mole of Al₂(SO₄)₃) = 27 moles of S

9 moles of Al₂(SO₄)₃ x (12 moles of O/1 mole of Al₂(SO₄)₃) = 108 moles of O

The number of moles of Al, S, and O atoms are 18, 27 and 108.