Swede - 12-12-2012 at 09:26
Sorry about all the Q. I've been asking lately, but my mind is whirling on my current electrochemistry project, Bismuth pyrochlores.
When electrolyzing chlorides to chlorates, pH is important, with 6.8 being optimum for the bulk (rather than anodic) reaction. The problem is that
the electrolyte is a noxious and highly concentrated brew of aqueous chlorine, hypochlorites, and chlorates. I have poisoned more than one pH probe
in short order, even when contact is minimized.
Generally, the cell goes alkaline, with uncontrolled cells easily going up to 10 or higher. HCl is added incrementally to maintain 6.8 or near
neutral.
Can the liquor to be tested be diluted, say 10:1, with distilled water, and the pH somehow extrapolated to what it would be if undiluted? This would
help with the probe poisoning problems. Accuracy not critical, +/- 0.1 or even 0.2 would be OK.
Many thanks