A sample is composed of 4.32 x 1022 H2SO4 molecules. What is the mass of the H2SO4?

Answer 1

First use avogadro's # to convert # of molecules to # of moles. Then convert moles of H₂SO₄ to grams using its MW.

4.32 x 10²² molecules H₂SO₄ x (1 mole H₂SO₄ / 6.02 x 10²³ molecules H₂SO₄) = 0.0718 mol H₂SO₄

MW of H₂SO₄ = 98.08 g/mol

0.0718 mol H₂SO₄ x (98.08 g H₂SO₄ / 1 mol H₂SO₄) = 7.04 g H₂SO₄