CaCl2
Harmless
Posts: 39
Registered: 14-1-2017
Member Is Offline
Mood: No Mood
|
|
Storage under water.
There are certain chemicals (Phosphorus etc.) that are often stored in water, but this has the problem that eventually the water evaporates. (Unless
you store it in a sealed ampoule, but then the water is generally kind of pointless.)
I wonder if you could use deliquescent salts to prevent evaporation of water.
A salt to be used so would need to be:
-Colourless
-Strongly deliquescent
-Unreactive towards most things.
This could be especially useful for element collections, since they usually have to be stable for years if not decades.
|
|
|
Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
Member Is Offline
Mood: Mood
|
|
Get a properly capped bottle and the water won't evaporate.
|
|
|
CaCl2
Harmless
Posts: 39
Registered: 14-1-2017
Member Is Offline
Mood: No Mood
|
|
Getting really tiny bottles with good caps is very difficult.
For example, for element collections that only have limited space for each element, especially for phosphorus which has many (4?) allotropes.
This would also provide protection from accidentally uncapped/badly capped bottles
|
|
|
Chlorine
Hazard to Self
Posts: 56
Registered: 26-11-2016
Location: Maine, USA
Member Is Offline
Mood: Brominated
|
|
I've never had a problem with water evaporation. I've had a 2g chunk of red phosphorus from my element collection stored under 20ml of water for about
4 months. As long as you put some sort of tape in the threads (Teflon, electrical, ChemiResist, etc) you should be fine.
|
|
|
Texium
|
Thread Moved
1-2-2017 at 07:23 |
CaCl2
Harmless
Posts: 39
Registered: 14-1-2017
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Chlorine  | | I've never had a problem with water evaporation. I've had a 2g chunk of red phosphorus from my element collection stored under 20ml of water for about
4 months. As long as you put some sort of tape in the threads (Teflon, electrical, ChemiResist, etc) you should be fine. |
OK, Well enough closed bottles seem to work.
Still, I wonder if using a hydroscopic salt would work for my specific situation.
The bottles I am using are very tiny, the smallest of these:
http://www.ebay.co.uk/itm/131612123546?_trksid=p2057872.m274...
Since their caps are made from cork, I used a 3D printer (In a library) to make plastic caps, but they aren't perfectly airtight even with added glue.
|
|
|
fluorescence
Hazard to Others
Posts: 285
Registered: 11-11-2013
Member Is Offline
Mood: So cold outside
|
|
Either use a more expensive bottle, refill your stuff, so maybe a larger bottle with more water and check on it once in a while. For comparison, as I
don't want any of my salts to get wet I check the caps of every bottle every three weeks, unscrewing them and rescrewing them to make sure nothing
gets in or out.
I guess the answer for you question is just store it better but the actual side question was more interesting actually ... you asked for a low
evaporation.
One thing I could think of is an ionic liquid maybe, they usually don't evaporate at all as they have nearly no vapour pressure. Well P4 is quite
reactive so you need to check a lot before doing that but it would be an interesting question...Also for element samples you don't use frequently but
want to protect them well enough...
|
|
|
j_sum1
Administrator
Posts: 6219
Registered: 4-10-2014
Location: Unmoved
Member Is Offline
Mood: Organised
|
|
There is an irony in someone named CaCl2 discussing storage under water. 
|
|
|
unionised
International Hazard
Posts: 5102
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
He's not wrong.
CaCl2 would work nicely.
|
|
|
CaCl2
Harmless
Posts: 39
Registered: 14-1-2017
Member Is Offline
Mood: No Mood
|
|
Yes, it seems like CaCl2 would work...
It even has the additional benefit of significantly lowering the freezing point of water. (So glass bottles won't crack if stored in a cold place.)
|
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
| Quote: Originally posted by Chlorine | | I've never had a problem with water evaporation. I've had a 2g chunk of red phosphorus from my element collection stored under 20ml of water for about
4 months. As long as you put some sort of tape in the threads (Teflon, electrical, ChemiResist, etc) you should be fine. |
Does red phosphorus need to be stored under water?
Signature ==== Is this my youtube page? https://www.youtube.com/watch?v=tA5PYtul5aU
We must attach the electrodes of knowledge to the nipples of ignorance and give a few good jolts.
Yes my evolutionary friends. We are all homos here. |
|
|
CaCl2
Harmless
Posts: 39
Registered: 14-1-2017
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by vmelkon | | Quote: Originally posted by Chlorine | | I've never had a problem with water evaporation. I've had a 2g chunk of red phosphorus from my element collection stored under 20ml of water for about
4 months. As long as you put some sort of tape in the threads (Teflon, electrical, ChemiResist, etc) you should be fine. |
Does red phosphorus need to be stored under water? |
I think generally only white phosphorus requires that.
|
|
|
Chlorine
Hazard to Self
Posts: 56
Registered: 26-11-2016
Location: Maine, USA
Member Is Offline
Mood: Brominated
|
|
| Quote: Originally posted by CaCl2 | | Quote: Originally posted by vmelkon | | Quote: Originally posted by Chlorine | | I've never had a problem with water evaporation. I've had a 2g chunk of red phosphorus from my element collection stored under 20ml of water for about
4 months. As long as you put some sort of tape in the threads (Teflon, electrical, ChemiResist, etc) you should be fine. |
Does red phosphorus need to be stored under water? |
I think generally only white phosphorus requires that. |
You should store all allatropes of phosphorus under water.
|
|
|
CaCl2
Harmless
Posts: 39
Registered: 14-1-2017
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Chlorine | | Quote: Originally posted by CaCl2 | | Quote: Originally posted by vmelkon | | Quote: Originally posted by Chlorine | | I've never had a problem with water evaporation. I've had a 2g chunk of red phosphorus from my element collection stored under 20ml of water for about
4 months. As long as you put some sort of tape in the threads (Teflon, electrical, ChemiResist, etc) you should be fine. |
Does red phosphorus need to be stored under water? |
I think generally only white phosphorus requires that. |
You should store all allatropes of phosphorus under water. |
Why?, most sources seem to suggest non-white phosphorus is air stable and non-toxic.
Even the sciencemadness wiki says water isn't required.
Honestly asking why they should be stored under water, not saying you are wrong.
|
|
|
Metacelsus
International Hazard
Posts: 2531
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline
Mood: Double, double, toil and trouble
|
|
At my academic research, I recently used a bottle of Raney nickel that had been stored under water for at least 4 years. The cap was sealed with
Parafilm, and less than 1 mL of water had evaporated. The Raney nickel was still good.
As a side note, if you ever use Raney nickel, watch out for it sticking to stir bars (it's somewhat magnetic). I nearly started a fire when I removed
my stir bar from the reaction flask.
|
|
|
PirateDocBrown
National Hazard
Posts: 570
Registered: 27-11-2016
Location: Minnesota
Member Is Offline
Mood: No Mood
|
|
I once had a 100g bottle of red P that had been clearly filled in the 80's. It was opened and used in the early 2000s, and was still good. It had
never had water in it. It was just a standard dry reagent bottle, no wax or parafilm of any sort.
|
|
|
DrP
National Hazard
Posts: 625
Registered: 28-9-2005
Member Is Offline
Mood: exothermic
|
|
| Quote: Originally posted by CaCl2 |
Getting really tiny bottles with good caps is very difficult.
For example, for element collections that only have limited space for each element, especially for phosphorus which has many (4?) allotropes.
This would also provide protection from accidentally uncapped/badly capped bottles |
Can you use paraffin or PTFE tape around the seal of the cap? Put it on the outside of the bottle (inside of the cap) and screw the cap over it - The
water wont evaporate out past that paraffin seal. Might work... will certainly buy you time at least.
\"It\'s a man\'s obligation to stick his boneration in a women\'s separation; this sort of penetration will increase the population of the younger
generation\" - Eric Cartman
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
