posted by bob .
A student is asked to prepare 250.0 mL of 3.5 M copper (II) sulfate from solid copper (II) sulfate pentahydrate. Describe how this solution should be made in the chemistry laboratory.
I'm not quite sure if you want 3.5M CuSO4 or 3.5M CuSO4.5H2O. I am assuming the former and want to start with CuSO4.5H2O.
How many mols CuSO4 do you want? That's M x L = 3.5 x 0.250 = about 0.9 but you need to do that more accurately.
Since there is 1 mol CuSO4 in 1 mol CuSO4.5H2O, you need the same 0.9 mol CuSO4.5H2O.
g CuSO4.5H2O = mol CuSO4.5H2O x molar mass CuSO4.5H2O