The maximum value of n in [Cu(EN)n]2+ for a Cu2+-EN solution is the key to a gravimetric method for determining the amount of Cu2+ in an unknown aqueous solution. In this method, we add excess EN and potassium tetraiodomercurate (II) (k2HgI4) to the solution, and the Cu2+ precipitates as [Cu(EN)n] [HgI4]. Assuming that the Cu2+ is the limiting reagent , what mass of [Cu(EN)n] [HgI4] should be isolated for each milligram of Cu2+ in solution