Chemical preservation and anhydrous form

I have bought some raw chemicals for my darkroom, some are anhydrous, how do I conserve and use them? I guess they quickly absorb water from air, so how do I open the container without letting water vapor in?

All the dusty chemicals are contained in white polypropylene jars, the cap is blue and fits tightly, the mouth is as large as the jar, it's a pop up type cap, no screw.
Here is a list of the chemicals I have, do I have to take any particular precaution in order not to ruin or chemically alter them?

Acetic acid glacial
Ascorbic acid
Boric acid
Citric acid
Ammonium cloride
EDTA
Pyrogallol
Potassium allum
Glycol propylene
Potassium bromide
Potassium carbonate anhydrous
Potassium metabisulfite
Sodium carbonate anhy.
Sodium metabisulfite anhy.
Sodium thiosulfate crystals
Sodium sulite anhy.
Sodium borate (borax) decah.
Sodium hydroxide (caustic soda)
TEA
Metol
Phenidone
Hydroquinone
Potassium iodite
Glycin
Amidol

PS: I bought a lot more that I need for most of the chemicals listed, if somebody needs some of these I can ship them to Europe, the price would be the same that I paid for them, PM for more info if interested.

The Potassium Carbonate needs to be kept well sealed as it absorbs moisture, but the rest should be fine.

Ian

Ian Grant said:

The Potassium Carbonate needs to be kept well sealed as it absorbs moisture, but the rest should be fine.

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Thanks for the info, I believe they are all well sealed, but when I open the container/plastic jar to take some of the chemical will enter in contact with air and moisture which will be absorbed, and the more chemical I use the more the jar becomes empty, more air with moisture will enter it, and even after I seal it the chemical will absorb water from the air in the jar.
Also, even if the chemical doesn't deteriorate the weight won't be correct, if I need 100g of Sodium sulfite anhy. and I take 100g of Sodium sulfite non anhy (mono, penta etc. hydrous) I will make a considerable mistake, and I can't know exactly how many particles of water it has absorbed.
Am I a little bit paranoid? How do they deal with this problem in labs?

Having run a lab we never thought about it, but with most on that list there's little to worry about. Just watch the Potassium Carbonate doesn't go gooey, the true word is to defeating my spelling

Yes chemicals do go off the Metabisulphites should be relatively fresh and have a sharp sulphur smell, but almost everything else will last well for years even if opened occasionally. As long as well sealed.

Ian

Nitai108 said:

Ammonium cloride
Pyrogallol*
Potassium carbonate anhydrous
Potassium metabisulfite**
Sodium carbonate anhy.
Sodium metabisulfite anhy.
Sodium thiosulfate crystals***
Sodium sulite anhy.**
Sodium hydroxide (caustic soda)
Metol *
Hydroquinone*
Potassium iodite (Iodide?)*
Glycin*
Amidol*

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Nitai;

Those marked * will oxidize in air and should be kept tightly sealed.

Those marked ** can absorb water from the air and/or be oxidized and should be protected.

Those marked *** might absorb water from the air depending on what form they are in. Sodium Thiosulfate Pentahydrate is most stable and will change little but all should be protected. They can oxidize.

The remaining chemicals in the list I left can absorb moisture but will not oxidize or decompose.

PE

Thanks Ron!

Well, I just had a thought. The Sodium Hydroxide is another case. It can also absorb CO2 from the air and lose alkalinity. I had forgotten to add that.

PE

Thanks a lot for the info PE!

Thanks to Ian too!

PS: potassium iodide, not iodite, typo mistake.