3
$\begingroup$

If I have a solution of dissolved $\ce{NaCl}$ or sugar (or some other ionic compound), is there a chemical I could add to it that would prevent crystal growth if I boil it down? I'm looking for it to remain as a very fine powder or to keep the crystals as small as possible.

$\endgroup$
1
  • $\begingroup$ Crystal growth isn't that easy to have- fine (mm) powders is normal with precipitation. If you seeking smaller than that, that is hard because the powders aggregate to larger particles. $\endgroup$ – user2617804 Jan 18 '15 at 9:20
6
$\begingroup$

Spray it as a fine mist into a drying chamber - the solvent will evaporate and you are left with a powder. No chemical involved though, but still process chemistry.

$\endgroup$
2
$\begingroup$
  1. If you decrease the solvent volume, the dissolved material will start to precipitate.

  2. Solubility most often increases with the temperature of the solvent.

  3. Slow decrease of the temperature or slow evaporation of the solvent at constant temperature mostly leads to slow crystallization, starting from a small(er) number of nucleation centres and typically results in the formation of less but larger, well-formed crystals.

Rapid decrease of the temperature with additional scratching the surface of the crystallisation vessel (beaker, etc.) with a glas rod, stirring, or sonification will typically result in precipitation of the solute in the form of smaller particles.

$\endgroup$
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.