Sciencemadness Discussion Board

Crystallisation Question

borontrichloride - 14-7-2017 at 00:14

To crystallise a complex, instead of heating it and bringing it back down to room temperature, has anybody tried simply putting it in the fridge? The lower temperature may work in the same way?

nezza - 14-7-2017 at 02:35

The idea of crystallisation to purify materials is to get the most product out of the solution. While taking a room temperature saturated solution and cooling it in the fridge may well give you some crystals you will get a much greater yield from a hot saturated solution which in any case for crystallising to purify materials I would put in the fridge anyway to maximise product yield. If you are crystallising to produce large crystals for display you need to allow them to grow very slowly, usually by allowing the solution to concentrate by evaporation at room temperature.

borontrichloride - 14-7-2017 at 06:05

So I could theoretically pour out my solutions onto a large, wide glass plate and allow the solvent to slowly evaporate - as this happens, crystals will form?

JJay - 14-7-2017 at 19:06

I tried that recently (in a large beaker, actually), and it seems to make nice crystals.

Nile Red grew some huge crystals of lead acetate in this video: https://www.youtube.com/watch?v=lOjLuJyMmUQ

borontrichloride - 14-7-2017 at 23:40

Thank for that. Any method I can find, that doesn't require heating transition metal solutions in the kitchen, I am down for!