# Electrolysis of Baking Soda separated by semi permeable membrane

I have dissolved baking soda in battery water (de-ionized), in a glass beaker and used a food handling glove (vinyl) as a semi-permeable membrane to separate a graphite electrode from a copper electrode. This is for an experiment that will use the copper electrode for the reaction and not the graphite electrode. When I apply a voltage $$(\pu{12 V})$$ and use a multimeter to measure the voltage, I get roughly $$\pu{11 V}$$ passing through the vinyl glove, however, no bubbles are produced, but if I remove the glove and have both electrodes in the beaker, then loads of bubbles are produced. So, will my experiment still work if the voltage is passing through the glove and there are no bubbles?

The primary problem is too low permeability = too high resistence of the gloves, causing high voltage drop where it should be minimal one.

The gloves are not hydrophilic enough for electrolyte soaking to get low resistance.

The remaining voltage - after subtracting the glove voltage drop - is not high enough to cause electrolysis by significant current.

You may try to use a salt bridge, as a passthru vessel with porous glass ends, or a gel formed from an electrolyte solution.

You may also want to try a compartment created from a glued filtration paper, or other hydrophilic porous material, impregnated by an electrolyte, preferably sharing one of ions with both free solutions.

For the paper, be aware of the same leveling on both compartments, otherwise. the paper will do its major purpose filtering. Eventually, more compact paper may be better, like the thick charts for paper painting.

• Ok, thanks for your help, I'll try the salt bridge and see what happens and then I'll reply on how good it was or if there are any difficulties. Your answer is much appreciated, cheers. – Justin Jan 3 at 10:51
• I used zinc with the copper and a porous plastic milk bottle as the divider and got 12 volts through, no voltage drop. But, still no fizzing, thinking that baking soda might not cause fizzing, water fizzes when electrodes are in the same container due to water splitting. Your idea of gluing filtration paper in as the divider sounds good, I'll give that a try. – Justin Jan 4 at 13:00
• A porous plastic milk bottle seems to have an internal contradiction for me. If it is a single layer plastic, it is not porous and hydrophilic. If it is porous and hydrophilic, it is a multilayer bottle with a least one layer not to be porous and hydrophilic. If it is like a foamed polystyrene cup, it is hydrophobic and gas bubbles is rather isolated then interconnected, not really porous much. – Poutnik Jan 4 at 13:06
• Thank You Poutnik !! The filter paper worked !! Interestingly I used 12 volts but got 6.67 volts through (I used coffee filter paper), but I got fizzing at both ends of the filter paper, so I must use hydrophillic cell dividers, makes sense, a good thing to learn. Děkuji moc za vaši pomoc Poutnik! Měj hezký den ! – Justin Jan 5 at 7:46
• You are very welcome, and thanks for the translation. :-) If the answer satisfied your question, it is supposed to mark the answer as the accepted answer. It may be helpful for future searching for related topics, as questions with accepted answers are marked differently. – Poutnik Jan 5 at 8:01