Question

A solution prepared by mixing 47.1 mL of 0.4 M AgNO3 and 47.1 mL of 0.4 M TlNO3 was titrated with 0.8 M NaBr in a cell containing a silver indicator electrode and a reference electrode of constant potential 0.175 V. The reference electrode is attached to the positive terminal of the potentiometer, and the silver electrode is attached to the negative terminal. The solubility constant of TlBr is Ksp = 3.6 × 10–6 and the solubility constant of AgBr is Ksp = 5.0 × 10–13.


(a) Which of the following expressions shows how cell voltage depends on [Ag ]?

b) What is the cell voltage when the following volumes of 0.8 M NaBr have been added? (b) 1.0 mL (c) 13.5 mL (d) 22.6 mL (e) 23.5 mL (f) 23.9 mL (g) 37.0 mL (h) 47.1 mL (i) 50.5 mL

I found part a) to be:

E = .175-(.799-.05916log(1/[Ag+])

I tried doing part b) over 10 times now and I can't figure it out.