Answer to Question #52791 in Other Chemistry for tone
IN H2S TITRATION WITH POTENTIOMETRIC INDICATION IN UOP-163 WHY ELECTRODE PREPARATION IS NEEDED?(SILVER ELECTRODE COATED WITH Ag2S?)
Electrode preparation in UOP-163 is needed because the hydrogen sulfide reacts with the silver surface, which leads to inaccuracy in the titration calculations.
4Ag + O2 +2H2S --> 2Ag2S + 2H2O