KonkreteRocketry - 16-3-2013 at 11:20
What can dissolve Sodium sulfate but not sodium chloride ? or the other way around ?
Any answers ? thx, i need to separate 2 solutions so i think i shall boil the water away and i have some different solvent like acetone, butane,
glycerin, ethanol, isopropyl alc, naphtha, liquid paraffin, toulene and some other house hold or common solvent, any thing ? thx.
macckone - 20-3-2013 at 14:39
The solubilities of sodium chloride and sodium sulfate are significantly different with temperature.
Sodium chloride solubility varies slightly with temperature while,
Sodium sulfate is much more soluble at 40C than 0C (above 40C the solubility decreases again).
So by heating to 40C and dissolving your combination you can dissolve the mixture.
Then cool to 0C and the Sodium Sulfate will selectively precipitate out.
The solution will still contain both but this allows purification of the Sodium Sulfate.
You can check wiki as it probably has other information about solubility.
AJKOER - 20-3-2013 at 17:45
Make a concentrated solution of the Na2SO4 so that you cannot dissolve any more Na2SO4 at 40 C.
Then, add some dry NaCl and stir.
What happens?
Cool the solution further and add more NaCl.
What happens?