So I'm running a current through distilled water with baking soda to produce hydrogen (to make stuff float :) ). I'm using carbon graphite electrodes and baking soda to avoid any dangerous gases like chlorine. Now its been almost a decade since I took chemistry classes and I'm wondering what other things are produced? I think CO2 is coming in somewhere from the baking soda? Does the graphite react as well? The reason I ask is because if I'm collecting the hydrogen gas from one electrode, I want to know how pure it is. So please let me know what other chemicals are being produced due to the graphite and baking soda (and anything else I didn't think of, nothing else I think since it's distilled water) and please tell me if those chemicals are gases and which electrode they are coming off of. Thanks!!