Why is gas visible rising from the cathode during water electrolysis?

[Bluskyz]

About 10 minutes ago, I was using my old playstation 2 power converter to perform electroysis on water. If I am correct, hydrogen is supposed to be formed at the cathode and hydrogen is colorless. However, when I started to see little bubbles rise the cathode which i assumed to be hydrogen, I could see a fade little gas rise from the water. I would like to know what this gas could be because I have heard that electrolysis can produce chlorine gas if you use table salt as an electrolyte. Also, oxygen is supposed to be formed on the anode but I think all of it is used to oxidize the metal anode. So how am I supposed to harness the oxygen?

 

[JohnRC]

About 10 minutes ago, I was using my old playstation 2 power converter to perform electroysis on water. If I am correct, hydrogen is supposed to be formed at the cathode and hydrogen is colorless. However, when I started to see little bubbles rise the cathode which i assumed to be hydrogen, I could see a fade little gas rise from the water. I would like to know what this gas could be because I have heard that electrolysis can produce chlorine gas if you use table salt as an electrolyte. Also, oxygen is supposed to be formed on the anode but I think all of it is used to oxidize the metal anode. So how am I supposed to harness the oxygen?

Any gas that you got from the cathode would certainly be hydrogen. It is possible that it would bubble off with a bit of water aerosol that might make the gas look white or grey

From the anode you can get oxygen, or chlorine if you have a high chloride concentration (concentrated table salt or hydrochloric acid as electrolyte) or oxidation of a metal anode. The only way to be sure of getting oxygen is to use a platinum, gold, or graphite anode.