Nitric acid getting weak? I am not sure if it gets weak. But, I think it does, so I keep mine in the freezer, out of the light.
I do everything by hook or crook and always learn the hard way, or when experiments go bad.
Like the still in the picture. I ran that one time and found some bugs that need to be changed.
It's a vacuum system. The one jug is a vacuum trap for the fumes, and has a vacuum regulater to keep the vacuum constant. The other jug is basically a vacuum resivour.
I did get some really good acid out of it, but not how I expected to get it because I don't know what I'm doing.