Electrode Measurements – Ch 15 Applications to potentiometric titrations, pH electrodes, quantitative measurements using ion-selective electrodes, etc. There are electrodes available for each of the 4 titration categories covered in this class: Acid-base – pH electrodes Precipitation – Ag/AgCl electrode, Ag+ specific ion electrode Complexiometric – Ca2+ specific ion electrode Redox – Pt electrode, Saturated Calomel Electrode (SCE)
Potentiometric Titrations (Sec. 10-4) Finding the Endpoint Numerically 1st der. = 2nd der. =
How Ion-Selective Electrodes Work (Sec. 15-3 – 15-5) Ideally responds to only the analyte ion in a solution. Produce a voltage because of a charge difference that develops inside and outside of the electrode. A. Liquid-Based Ion-Selective Electrodes
Valinomycin is used in K-electrodes
Ca2+ Ion-Selective Electrode
pH Measurement with a Glass Electrode
Acid and Alkaline Errors of pH Electrodes
B. Solid-State Ion-Selective Electrodes
Electric Potential Difference for an Ion-Selective Electrode e.g. pH electrode
Detection Limits and Interferences Pb limit of detection =