What mass of copper sulfate (CuSO4) contains as many molecules as there are in 2.8 g of phosphorus oxide (P2O5)

Given:
m (P2O5) = 2.8 g

To find:
m (CuSO4) -?

1) M (P2O5) = Mr (P2O5) = Ar (P) * N (P) + Ar (O) * N (O) = 31 * 2 + 16 * 5 = 142 g / mol;
2) n (P2O5) = m (P2O5) / M (P2O5) = 2.8 / 142 = 0.02 mol;
3) n (CuSO4) = n (P2O5) = 0.02 mol;
4) M (CuSO4) = Mr (CuSO4) = Ar (Cu) * N (Cu) + Ar (S) * N (S) + Ar (O) * N (O) = 64 * 1 + 32 * 1 + 16 * 4 = 160 g / mol;
5) m (CuSO4) = n (CuSO4) * M (CuSO4) = 0.02 * 160 = 3.2 g.

Answer: The mass of CuSO4 is 3.2 g.