What is going on with some of my chemicals?

[vjuliano]

I have noticed some odd behavior of some of my stored chemicals recently. My sodium carbonate which was originally powder now seems to have liquefied.

My 2% Benzo solution seems to have formed a thick crystal structure inside, almost looking like fiberglass. Both seem to be sealed fairly well. The sodium carbonate is in a refused, but cleaned jar, and the benzo is in a brown glass bottle like many of my chems.

Both have been stored for less than a year. The rest of my chems, both powder and liquid seem to be fine. Temp is always basic room temp and there is no excess moisture. Its stored in a closet in my bedroom.

I attached some pictures below if anyone has any ideas what happened to either.

Thank you

 

[Anon Ymous]

Benzotriazole isn't very soluble and 2% is perhaps at the limit of practicality. That said, if the solution's temperature gets below a certain threshold, then recrystallization occurs, which is what happened to your solution. You got some very nice benzotriazole crystals. You can warm it up and stir it to make it redissolve, but I'd further dilute it to twice its volume and make a 1% solution.

Sodium carbonate is hygroscopic and tends to absorb water from the atmosphere, but truth be told, I'm surprised that it got so ugly. I've seen other compounds becoming a soggy mess (ammonium nitrate), but stored in an open bag.

 

[koraks]

Its stored in a closet in my bedroom.

A bedroom is typically a fairly moist room. It has to do with your breathing in it for 6-9hours every day. Depending on (lack of) ventilation, a bedroom may have fairly high relative humidity.
Still, of course it's perfectly feasible to store chemicals like these in a bedroom, as long as appropriate containers are used. As you have noticed, not all jars seal well. Your carbonate jar definitely doesn't.
As to the benzotriazole: what @Anon Ymous says. It is of limited solubility. A 1% solution typically keeps quite well.

 

[vjuliano]

This all makes sense. Thanks. I usually use better containers but hoped I could get away with the recycled jar. I was just amazed at the amount of moisture the carbonate pulled in to be completely submerged. I figured it would just get moist and pasty. Not that Im going to do it, but if I was to evap off the water in an oven or something, would it theoretically go back to original form?

 

[koraks]

Yes, you can evaporate it, but your best bet would then to do it completely until you have anhydrous carbonate, otherwise you'll end up with molar mass problems. Look up the different hydrates of sodium carbonate for more info.

 

[Kino]

I have found that regular pint to quart Mason Canning Jars with a new ring, lid and a layer of cling wrap (for food) under the lid, work very well for storing chemistry. I keep my bulk chemicals in an old photocopier paper cardboard box that has a layer of newspaper over the jars to keep out the light. I have quarts of Elon and Hydroquinone that are over 20 years old; they are fine.

Occasionally, I have to replace the rings, which tend to rust, but the lids and cling wrap do not rust for some reason.

 

[vjuliano]

I use ball jars as well. I just didnt have one at the time, and it was easier to fit the pickle jar on the crowded shelf than the bag that the chems came in. If I buy from reputable sources, they usually come in good containers anyway. But sometimes Im cheap and want to see whats up with the cheapest chems ebay has to offer.

 

[Andrew O'Neill]

Holy cow that's weird, especially what happened to your sodium carbonate. I have a few plastic jars with electrician tape on them. I've never seen this happen.