stiochiometry mass to mass calculations

Question

1. how many grams of sodium sulfate are produced when 15.0 g of sulfuric acid is reacted with an excess of sodium hydroxide
2. what mass of anhydrous copper (II) sulfate can be obtained by heating 125 g of copper (II) sulfate pentahydrate?

Answer 1

H₂SO₄ + 2NaOH ==> Na₂SO₄ + 2H₂O ... balanced equation

Using stoichiometry and dimensional analysis, we have...

15.0 g H₂SO₄ x 1 mol/98 g x 1 mol Na₂SO₄/mol H₂SO₄ x 142 g/mol Na₂SO₄ = 21.7 g Na₂SO₄

CuSO₄•5H₂O ===> CuSO₄ + 5H₂O ... balanced equation for heating the copper sulfate pentahydrate

125 g CuSO₄•5H₂O x 1 mol/249.7 g x 1 mol CuSO₄/mole CuSO₄•5H₂O x 159.6 g/mol CuSO₄ = 79.9 g CuSO₄