I want to create a somewhat pure oxygen gas from electrolyzing water and using sodium bicarbonate as an electrolyte.

How can I harvest the oxygen once it is released from the water, and store it in a container without adding oxygen to the existing air in the container? Meaning that I want pure oxygen in the container and not normal air.

  • 1
    $\begingroup$ Hello and welcome to Chemistry.SE! I suggest taking the short tour if you have any questions about how this site works. Regarding your question, the simplest approach to this may be to displace the water from a full, inverted container like a test tube. If you could rig some kind of inverted funnel over the anode (in the water) with a hole at the top for a short straw that goes into the inverted container, that might do what you need. This is really a mini-engineering question as you've already done the chemistry in creating the oxygen, but maybe someone will have a good idea. Good luck! $\endgroup$ – airhuff Mar 1 '17 at 0:56

I think the simplest approach is to fill a test-tube with your electrolyte solution, seal the open end with your latex-glove covered thumb, then immerse the sealed end in your cell. If you can tilt your anode several degrees from the perpendicular, you should get a stream of oxygen bubbles that you can then catch with the test tube. You certainly won't get them all but it shouldn't be a problem to get 3/4 of them anyway. If you have trouble inverting the test tube without having a little air left, just slide some flexible tubing to the top and suction out the air. Take care to watch the level of your electrolyte as the solution that is displaced from your test tube will of course be filling your cell.

After you have collected all of the oxygen you need, seal the open end of the test tube with a piece cut from a latex glove and a rubber band. You will then have a test tube filled with oxygen gas and any residual electrolyte solution.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.