1. The problem statement, all variables and given/known data Give the reactions that take place when the following solutions are passed through a Jones-redactor (amalgamated zinc), and calculate the equilibrium constant at 298.15 K for each. 0.01 mol/dm3 CuCl2 0.01 mol/dm3 CrCl3 0.01 mol/dm3 NH4VO3 (pH =1) Data: Couple, E° value Cu2+/Cu 0.34 Cr3+/Cr –0.74 Cu2+/Cu+ 0.16 Cr2+/Cr –0.90 VO2+/VO2+ 1.00 Zn2+/Zn –0.76 VO2+/V3+ 0.36 TiO2+/Ti3+ 0.10 V3+/V2+ –0.255 Ag+/Ag 0.80 V2+/V –1.13 Fe3+/Fe2+ 0.77 2. Relevant equations The usual equations - ΔG=-nFE, ΔG°=-nFE°, ΔG=-RTln(K). 3. The attempt at a solution --- So one redox equation going on for all cases is the Zn2+/Zn couple, E°=–0.76, Zn2+ + 2e- ::equil:: Zn. The forward reaction will occur if E°[Zn2+/Zn]>E°[Couple j], where j is the couple which represents the redox equation occurring on the other side. But how do I know which equation j will be, from all the different choices we get for each case? For example, in the first case, is it Cu2+ + e- -> Cu+, Cu+ + e- -> Cu, or Cu2+ + 2e- -> Cu which we need to consider as couple j against E°[Zn2+/Zn]? And how do we determine which equation we need to take for all three cases. I have seen the solutions but this question, of which one to choose of the possible equations, is not properly explained.