I'm trying to make chlorine from bleach (4.5% w/w of NaClO) and some sanitizer stuff (8% w/w of HCl), but I can't really come up with a way to get the chlorine out of the mixture. My current approach was to mix both together in a 1 L glass bottle and with the amounts I added it should've produced ~ 3 L of chlorine. I put a balloon on top of that bottle but it didn't really inflate as the pressure was too low (see pic) and on top of that I forgot that chlorine is denser than air, and as such wouldn't even be in the balloon. I'm doing all of that with commonly available stuff from the supermarket, does anyone have an idea how to do it better?