Molarity can be defined as the number of moles of solute in 1 L solution. Molarity of Na₂SO₄ solution - 0.200 M this means there are 0.200 moles in 1 L solution Molar mass of Na₂SO₄ - 142 g/mol therefore mass of Na₂SO₄ in 1.00 L - 0.200 mol x 142 g/mol = 28.4 g a mass of 28.4 g of Na₂SO₄ is present in 1.00 L
