Plate Conditioning Brown Scum Observations

I perform a 34 minute test to further condition the simpleton plate assembly and provide observations as I go.




What I learned.

1. The "scum" forms within 2-4 minutes.

2. The "brown" begins forming shortly afterward and slowly builds concentration throughout the test.

3. The "scum" doesn't seem to progress in volume along with the test.

4. The "scum" leaves a film on a spoon that is inserted into it while the "brown" does not seem to stay on the spoon with the "scum".

5. The "scum" isn't impermeable as larger bubbles trapped in the scum will pop. Tiny bubbles do not seem to pop as readily leading me to think the scum surface tension is higher than just the electrolyte.

6. The scum with trapped bubbles behaves like thick wet soap bubbles. To watch it during electrolysis, it behaves nearly like oil on water when it's disturbed by the fluid motion caused by electrolysis. So it has its own composition which is unlike the water/NaOH mixture.

7. After stoppng electrolysis, the "scum" dissapates rapidly, almost as fast as the trapped bubbles do.

8. The "brown" goes into a kind of suspension and hovers near the surface but not necessarily on the surface.

9. Disturbing the "brown" causes it to slowly sink.

My Theories

1. The "scum" and the "brown" are seperate compounds.

2. The scum seems to be a byproduct of the electrolysis, but to a limited extent.

3. The brown evidently is rust, but requires chemical analysis.

4. The scum may or may not be a distinct compound resulting from the electrolysis. It does seem to dissipate shortly after electrolysis stops.