The table below summarizes the emf observed for the cell Pd

Chapter 7, Problem 7.22

(choose chapter or problem)

The table below summarizes the emf observed for the cell Pd |H2(g, 1 bar) | BH(aq, b), B(aq, b) | AgCl(s) | Ag. Each measurement is made at equimolar concentrations of 2-aminopyridinium chloride (BH) and 2-aminopyridine (B). The data are for 25C and it is found that E 7 = 0.22251 V. Use the data to determine pKa for the acid at 25C and the mean activity coefficient (}) of BH as a function of molality (b) and ionic strength (I). Use the extended DebyeHckel equation for the mean activity coefficient in the form log }= kb where A = 0.5091 and B and k are parameters that depend upon the ions. Draw a graph of the mean activity coefficient with b = 0.04 mol kg1 and 0 I 0.1. b/(mol kg1) 0.01 0.02 0.03 0.04 0.05 E(25C)/V 0.74452 0.72853 0.71928 0.71314 0.70809 b/(mol kg1) 0.06 0.07 0.08 0.09 0.10 E(25C)/V 0.70380 0.70059 0.69790 0.69571 0.69338 Hint. Use mathematical software or a spreadsheet.