I'm doing a high school chem project where I am making a calibration curve of copper(II) sulfate for spectrophotometry in which I make solutions with five different concentrations. The most concentrated one being what I though was 2 molal.
But I noticed that in that solution I could see specs of crystals floating around still after stirring for a while, and it did not want to dissolve completely.
It says on Wikipedia that copper(II) sulfate has a solubility of 1.26 molal (20 °C) in water. Does that mean that I can't have a solution with a concentration of 2 molal at that temperature?