Electrogravimetric analysis with control of the cathode potential is proposed as a means for separating Bi3+ and Sn2+ in a solution that is 0.250 M in each ion and buffered to pH 1.95.
(a) Calculate the theoretical cathode potential at the start of deposition of the more easily reduced ion.
(b) Calculate the residual concentration of the more readily reduced species at the outset of the deposition of the less easily reduced species.
(c) Propose a range (versus SCE), if such exists, within which the cathode potential should be maintained. Consider a residual concentration less than 10-6 M as constituting quantitative removal.