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Salt bridge membrane electrolysis not working

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sprotz:
I am trying to do membrane electrolysis of sodium bicarbonate by using a salt bridge which is a paper towel soaked in electrolyte and one end dipped in bicarbonate solution, the other dipped in plain water. Using carbon electrodes, one in each solution and 12v DC 3A, I switch on the power but nothing happens.
The goal is to form sodium hydroxide, but no electrolysis occurs. I tried to test the system on two containers with salt solution bridged by a membrane. A small amount of bubbling happens.

So I think maybe resistance is too high through the membrane? Or that plain water is just too weak an electrolyte?

Borek:

--- Quote from: sprotz on May 16, 2020, 10:42:01 AM ---So I think maybe resistance is too high through the membrane? Or that plain water is just too weak an electrolyte?
--- End quote ---

Or even both.

What is the current?

sprotz:
3.25 Amps, 12 Volt power adapter.
But I have noticed the electrolysis picking up after some time. Bubbling is visible and increasing. It seems it needs time for the sodium ions to travel across to the other cell. Adding a little hydroxide to the pure water cell will speed things up.

Borek:

--- Quote from: sprotz on May 16, 2020, 01:04:14 PM ---3.25 Amps, 12 Volt power adapter.
--- End quote ---

Is that measured current, or the rating of the DC unit you are using?

sprotz:
That is the rating on the power adapter.

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