posted by Amanda .
How do you prepare a 0.4 M soultion of copper sulfate in water starting with solid copper sulfate and water?
0.4 M soln means 0.4 mol/L soln.
mols = g/molar mass
0.4 mol = g/molar mass.
Calculate molar mass CuSO4, solve for grams, weigh that many grams, add to a 1 L volumetric flask, add some water, swirl until all of the salt is dissolved, make to the mark with distilled water, shake to mix thoroughly.