RAPID-DETERMINATION OF DIVALENT TIN IN ALKALINE TIN-PLATING SOLUTION BY DIRECT POTENTIOMETRY

A novel method for determination of Sn(II) in alkaline tin plating solutions by potentiometry has been developed, Potassium ferricyanide is added to form an equilibrium of both Sn(OH)(6)(-2)/HSnO2- and Fe(CN)(6)(-3)/ Fe(CN)(6)(-4) in the solution, The quantity of Sn(II) in the solution is obtained by measuring the potential of Fe(CN)(6)(-3)/Fe(CN)(6)(-4), which is rapid, with a stable reading within three to six min, The potential difference becomes as great as 50 mV when the content of Sn(II) is 0.02 g/L and 0.20 g/L, respectively, The average success rate for the determination of Sn(II) in alkaline tin plating solutions by this method is 95.2 percent, with a relative standard deviation of 1.2 percent.