Different chemicals have different "shelf lives." But this "shelf
life "concept usually depends to a considerable extent on just how
pure the reagent is to begin with, and how pure you need it to be
fore your particular use, and whether it has been dissolved (if a dry
chemical) or diluted (if a liquid) an so on and so on.
Nitric acid (con & dilute), Sulphuric acid (von and dilute)
You probably wouldn't have any trouble with shelf life with these
Methylene Iodide, Benzyl benzoate
I'll pass to John on these two!
This I wouldn't keep around for too long. Realize that the fumes can
be quite poisonous to breathe!
If you're talking about diethy ether, I hope you realize that this
one, when sitting, can build up explosive substances in it that just
a jarring can set off. Also it is quite flammable, just a spark can
set it off. The container needs to ALWAYS be grounded, and it needs
to be kept in a hood with an explosion-proof motor in it. I wouldn't
keep this one around for long. Isn't there something else you can
use instead? What are you using it for?
Pass. (But I don't like it!)
I'm trying to figure what on earth you would be using this stuff
for!!!??? *Many are quite dangerous if you don't know just what you
The liquids used in developing film!
This depends to a great extent on -- what kind of film? AND Which
particular solutions are they? When you say "the liquids used", I am
assuming here that you mean the kits you may buy to process film in.
Your best bet here is to contact the manufacturer of the kits.
Developers don't keep for long in liquid form. The air in the
solutioin (and in the bottle if not full) will oxidize the developing
agents. Things like stop baths are usually just dilute acetic acid
and will keep indefinitely. Fixing baths -- if it uses an ammonium
hypo, such as in the quick fixers, they can decompose (precipitating
out sulfur) fairly quickly, once they have been used. Sodium hypos
last longer, but will also precipitate out sulfur eventually.
If, on the other hand, you are talking about the liquid chemicals
that you use to hand-mix the sollutions; they are mostly pretty
stable. The dry chemicals are also mostly pretty stable, except for
the developing agents, which will oxidize (and thus lose "strength").