04-20-04 04:52
No 501777
can anyone tell me if this latex tubing with withstand a little HI(aq) if used to connect glass tubing between flasks and condenser?
(Hive Bee)
04-20-04 05:33
No 501781
Why are you using tubing and not a stillhead?
As long as its weak conc HI(aq) and not gas it SHOULD be able to put up with a little amount, but after a little bit you will need to replace the tube...
(Hive Bee)
04-20-04 17:53
No 501899
my experience with latex and HI has been perfectly fine, but this was for short hot reactions and no condenser (modified curbshot method). I don't know how it would stand up to a long wet reflux. I would think it would be better to bore a solid piece of rubber (maybe a stopper) and use it as a sleeve to hold the two glass tubes together. The bonus would be that it would be somewhat rigid and support some of the weight of whatever is above it. Plus the rubber lasts longer and handles higher temperatures by forming a carboniferous crust on the surface which is fairly chemically resistant after a bit of exposure to high temperature or reactive chemicals (unless they dissolve it) or both.
(Hive Bee)
04-21-04 14:54
No 502139
excellent idea on the stopper. i think that's the route i'll go. i'm not willing to buy a stillhead right now because i didn't get ground glass joint because i'm new and want to get some experience so i will know what i really want for labware
(Hive Bee)
04-21-04 15:58
No 502145
The ridiculous cost of ST ground glass joints compared with simple fire-polished ends and stuff, on a low budget, with limited experience... makes no sense.
In the olden days chemists always had to put up with rubber joining thingies and stuff everywhere (although when i say olden days i mean like 80 years ago and longer) and although there is some issues of contamination from the slow decay of rubber, for simple beginning chemistry it makes a lot of sense to use the cheaper equipment. beginners often break things. To illustrate: an old-style liebig condenser with only a drip tip end and an open beaded rim edge on the other for stuffing a cork into it, 200mm long, costs about us$20. The same liebig with 24/40 joints costs about us$50. When you consider the cost of starting up and replacement, it is obvious that if you don't need vacuum bla bla bla, you don't need ground glass unless you feel confident you won't break it and not be able to replace it.
(Hive Bee)
04-21-04 16:02
No 502147
elfspice: i agree with you completely. SWIM got his first condenser, of the style you describe but 500mm and i'm sure it will be in service until i break it :)