The equation for copper(II) sulfate dissolving in water is: CuSO4(s) => Cu2+(aq) + SO42-(aq) There is no need to add water to the equation. By writing the states (aq = aqueous) of the ions, it is understood that water has been added. Thus the species present in solution are: Cu2+(copper (II) ion) and SO42- (sulfate ion). The color of a solution is determined by the characteristic color of the species present in the solution. Cu2+ has a characteristic blue color, while SO42- is colorless. Thus the solution appears blue overall. Solution The equation for copper(II) sulfate dissolving in water is: CuSO4(s) => Cu2+(aq) + SO42-(aq) There is no need to add water to the equation. By writing the states (aq = aqueous) of the ions, it is understood that water has been added. Thus the species present in solution are: Cu2+(copper (II) ion) and SO42- (sulfate ion). The color of a solution is determined by the characteristic color of the species present in the solution. Cu2+ has a characteristic blue color, while SO42- is colorless. Thus the solution appears blue overall..