Chapter 23, Problem 23.20QAP

The cell Ag|AgCl(sat’d)||H⁺(a = x)|glass electrode has a potential of —0.2094 V when the solution in the right-hand compartment is a buffer of pH 4.006.
The following potentials are obtained when the buffer is replaced with unknowns: (a) —0.2806 V and (b) —0.2132 V. Calculate the pH and the hydrogen ion activity of each unknown. (c) Assuming anuncertainty of 0.001 Vin the junction potential, what is the range of hydrogen ion activities withinwhich the true value might be expected to lie?