Electra
Hazard to Others
Posts: 179
Registered: 11-12-2013
Member Is Offline
Mood: No Mood
|
|
Does salting out work with dissolved gases, pushing them out of solution?
If I had some water with a dissolved gas in it like ammonia, or some acid gas, would saturating the solution with a salt force the gas out?
I think yes by virtue of equilibrium and ionic solubility difference, but I can't find anything online about it.
|
|
|
DraconicAcid
International Hazard
Posts: 4278
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
I believe so, but I've never seen anything quantitative on it. As long as the salt isn't going to react with the gas you're trying to eliminate from
solution.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
gsd
National Hazard
Posts: 847
Registered: 18-8-2005
Member Is Offline
Mood: No Mood
|
|
Yes. If you add CaCl2 in 30 % HCl then Hydrogen Chloride gas "salts out".
gsd
|
|
|
DutchChemistryBox
Hazard to Self
Posts: 74
Registered: 24-3-2013
Location: Strasbourg
Member Is Offline
Mood: No Mood
|
|
Yes it works. This principle is also commonly used with gas chromatography headspace injections. If you search on that terms you will find more about
it.
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Does anybody have an experiment in mind to test this ?
|
|
|
DraconicAcid
International Hazard
Posts: 4278
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
You could take solutions of concentrated ammonia, add various salts to some of them, and titrate to see what's left. Pipetting out solutions of conc.
ammonia isn't fun, but it could be done.
[Edited on 17-12-2015 by DraconicAcid]
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Science not Fun ?
What ?
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
A nice example is adding table salt to carbonated soft drinks. You get a lot of bubbles when the salt dissolves. CO2 is "salted out".
|
|
|
DraconicAcid
International Hazard
Posts: 4278
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
Quote: Originally posted by woelen  | | A nice example is adding table salt to carbonated soft drinks. You get a lot of bubbles when the salt dissolves. CO2 is "salted out".
|
Yeah, but that solution is supersaturated, so it's possible that the salt simply gives a nucleation site for the bubbles to form.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Very simple to test woelen's excellent practical suggestion:
1) add 2g solid granulated table salt to a small bottle of fizzy drink.
2) Add just enough water to 2g of salt to dissolve it, then add that saturated solution to another identical bottle of fizzy drink.
In both cases immediately stick a Balloon on top of the bottle.
Observe Balloon size, and Measure the expansion as accurately as possible.
ANYBODY can do this (which is why woelen's suggestion is excellent) !
I Certainly will, in the interest of Science, and it sounds like a bit of fun as well.
Wonder if anybody else is actually interested in Science on this board ...
Measurements and experimental results will tell.
|
|
|
DraconicAcid
International Hazard
Posts: 4278
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
| Quote: Originally posted by aga | Very simple to test woelen's excellent practical suggestion:
1) add 2g solid granulated table salt to a small bottle of fizzy drink.
2) Add just enough water to 2g of salt to dissolve it, then add that saturated solution to another identical bottle of fizzy drink.
In both cases immediately stick a Balloon on top of the bottle.
Observe Balloon size, and Measure the expansion as accurately as possible.
ANYBODY can do this (which is why woelen's suggestion is excellent) !
I Certainly will, in the interest of Science, and it sounds like a bit of fun as well.
Wonder if anybody else is actually interested in Science on this board ...
Measurements and experimental results will tell. |
Better yet, place the salt (or solution) inside the balloon, so it can be added while the balloon is in place.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Makes it more difficult to do.
Not all balloons are created equal, yet two from the same pack will be close enough for the purposes of this experiment.
Edit:
Just thought : the two bottles must have about 30ml removed before starting, or the saturated solution will not fit in the bottle.
[Edited on 17-12-2015 by aga]
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
Compare solubility of gases in water and in seawater, you will get your answer... soluble salts decreases the solubility of gases into water 
The solubility and saturation value for gases in sea water increase as temperature and salinity decrease and as pressure increases.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
