how would you make a solution of Copper (II) Sulfate Pentahydrate to achieve 150, 200, 250 and 300 mgL−1 concentration of copper? I do not have the anhydrous version of the solute. Also, when I dissolve it in water, does it become acidic? If so, how would I maintain it at pH 7 without messing up the concentration? I am going to use the solution for adsorption studies if anyone is asking. thanks for the replies!