Potentiometry

A standard electrochemical is constructed based on the redox equation and has a potential of 1.25 volts.      5 Fe(s) + 2 MnO­4– + 16 H+ → 5 Fe2+ + 2 Mn2+ + 8 H2ODescribed below are changes that are made to this standard cell. Circle one answer only as to whether the changes will result in higher, lower, or no change to the cell potential compared to the standard cell. a) [MnO­4–] is doubled:                    higher          lower          no changeb) [Mn2+] is doubled:                       higher          lower          no changec) The pH is changed to 7.5:          higher          lower          no changed) The amount of Fe is doubled:   higher          lower          no change

Given the following redox reaction: Ce(s) + Al3+ → Al(s) + Ce3+Half Cell PotentialsCe3+ + 3 e– → Ce(s)        E° = –2.336 Al3+ + 3 e– → Al(s)          E° = –1.677Find the equilibrium constant for the reaction above.