Sciencemadness Discussion Board

Storage of potassium chlorate

arsonist - 20-11-2014 at 02:10

Hi, sorry for the silly question but I couldn't find an answer in Google. Is it Ok to store potassium chlorate(KClO3) in glass bottle tightly closed? Should it also be stored away from sunlight or it doesn't matter because my bottle is from brown glass? Thanks.

HeYBrO - 20-11-2014 at 02:36

Yes that is fine. And just a friendly reminder, when you post questions without reference or simple ones like this it should go in beginnings or you could try The short question thread in miscellaneous :)

[Edited on 20-11-2014 by HeYBrO]

[Edited on 20-11-2014 by HeYBrO]

greenlight - 20-11-2014 at 02:43

I looked up a bunch of material safety data sheets and they all say store in a cool, dry place and keep it in the original container but none specify what type of container the original was.
When I had some Potassium chlorate stored for a couple of months it was in a plastic food storage type container with a screw-top lid and I didn't have any problems. I can't see glass being any different and it doesn't say anything in the MSDS's about not using glass.
I don't think the sunlight degrades it but it would be best to keep it out of the sun and heat anyway, I had mine in a cool cupboard.

woelen - 20-11-2014 at 02:55

Potassium chlorate is very easy to keep around. Any container with a decent seal is suitable. KClO3 is not hygroscopic and at room temperature not overly reactive. I have some KClO3 in the form of small crystals, stored already for more than 30 years in a glass jar with a hard plastic screw cap. It still is as good as when I purchased it. A few years ago I made some KClO3 from KCl and this I store in a plastic jar with a plastic screw cap. This also still is in perfect condition.

arsonist - 20-11-2014 at 06:37

Ok, thank you for your replies :)

AJKOER - 20-11-2014 at 09:51

The only thing that may cause a large potential problem is inadvertently exposing an opened vessel of your KClO3 to a sensitizer (at which point, you may have formed a small amount of a dangerous/powerful contact explosive which could serve as a primer for the rest of the pure KClO3). Inserting a dirty scooper, for example. While not likely, soot from polluted air or you burned something may fill the role also. Sulfur exposure also but probably even less likely.

So, storing it is not much of an issue. It is how careful you are after opening in allowing possible problematic contamination, after which point the magnitude and your proximity to a potential rapid decomposition event would be the issue.

MrHomeScientist - 21-11-2014 at 07:41

Quote: Originally posted by greenlight  
I looked up a bunch of material safety data sheets and they all say store in a cool, dry place and keep it in the original container but none specify what type of container the original was.

That's standard lingo for all MSDS sheets. It just means you shouldn't store your chemicals on the windowsill of the garden shed in the middle of summer. And 'original container' means the bottle the item was purchased in - the MSDS writers assume that the manufacturer knew what they were doing when they packaged the item.
In this case, any type of bottle is fine and the chemical is perfectly stable under normal storage conditions on a shelf in your lab.

Also, don't let Joker scare you; he likes to post untested syntheses and extremely improbable scenarios for fun.

macckone - 21-11-2014 at 09:57

Improperly stored chlorate is likely to disproportionate to perchlorate
and chloride. Light and heat will help this process along.
In fact at high temperatures (80C) it is pretty quick.

woelen - 21-11-2014 at 11:08

@AJKOER: What you describe will never happen in practice. Pure KClO3 simply does not detonate. If contamination is added to the KClO3, then part of it may react, but the excess amount of KClO3 does not react.

@macckone: I have had KClO3 at 100C or so for hours, but no noticeable amount of chloride was formed. The disproportionation which you mention indeed can occur, but it requires temperatures of 300 C or so. Thermodynamically this disproportionation seems to be favorable, but practical reaction speed is increadibly low, even at 100 C or so. The kinetic mechanism only becomes feasible at 300 C or so.

macckone - 22-11-2014 at 02:15

Quick is relative.
Storage at 80C is days to weeks not hours.
I usually think of storage in months so weeks is
Relatively short.