Sciencemadness Discussion Board


Pixicious - 11-3-2008 at 03:54

Say I had some chalk and chloroform, I've just been researching both of these.

How soluble is chalk in chloroform and how do I know whether a solid and a liquid are soluble together?

Many thanks.

not_important - 11-3-2008 at 05:09

You can check in the CRC or Lange's handbook, or go to the Internet Archives and search text files for 'solubility' which gives you results like this:

Or you can remember that ionic compounds generally have low solubilities in non-polar solvents. That's just a guideline, NaI dissolves fairly well in methanol and acetone, but the NzCl doesn't.

Or you could put a gram of CaCO3 in a test tube, pour say 5 cc of chloroform onto it, loosely stopper it and let it sit for an hour. While it's sitting, weigh a small beaker. Carefully pour the chloroform from the test tube through a filter into the beaker, and allow it to evaporate on its own, then weigh it to determine the approximate solubility you seek.

JohnWW - 11-3-2008 at 05:58

Chalk (CaCO3) would be EXTREMELY insoluble in something like chloroform, given that it is an ionic solid with a crystal-lattice energy that precludes its being signioficantly soluble even in highly polar ionizing/protic solvents like water (unless CO2 is also present in solution, which reacts with it to form the sparingly soluble bicarbonate, or other acids are present which are stronger than carbonic acid).