or the solution containing Zn2+(aq), n is 2, so the MM/n ratio will be the molar mass of Zn divided by 2: MM/n = (65.39 g/mol) / 2 = 32.70 g/mol Compare this theoretical value with your experimental result. If the plating efficiency is significantly less than 1, say it is 0.55, how would the observed MM/n ratio compare to the theoretical value?