How many grams are in 4.5 x 10^22 atoms of Copper(II) Sulfate?

Answer 1

Obviously you mean molecules instead of atoms of CuSO₄. Use Avogadro's Number to find moles, then multiply by molar mass: (4.5 x 10²² molecules) * (1 mol whatever / 6.022 x 10²³ particles) * (159.6g CuSO₄ / 1 mol CuSO₄) = 11.9 ≅ 12 g CuSO₄ (two sig figs).