Sciencemadness Discussion Board

Evaporating a solution of HCL without vacuum?

Agent MadHatter - 22-8-2009 at 16:20

How would you evaporate a solution of HCL without a vacuum and no heat?

I don't have a vacuum I can use other than my house vacuum, and If I use heat the salt in the HCL will isomerize according to the book. So how would you evaporate it? Any way to do this?

12AX7 - 22-8-2009 at 18:46

Drying agent? Dessicator, H2SO4, ...???

Tim

carbon chloride - 22-8-2009 at 19:15

well if you just leave it out at room temperature it should eventually evaporate... might take a long time though.

crazyboy - 22-8-2009 at 19:22

Let it sit in a Pyrex or other glass baking tray maybe with a small fan blowing. It will evaporate pretty quickly then recrystallize to get rid of and dirt/dust which will have fallen in.

Or try freeze precipitating the crystals.

BromicAcid - 22-8-2009 at 19:47

Sparge it with dry air.

carbon chloride - 22-8-2009 at 20:24

interesting crazyboy, so if you have any solution where water is the solvent, freezing it would make all of the solute precipitate?

kclo4 - 22-8-2009 at 20:39

Generally if you heat a solution, it is able to dissolve more, and when you cool a solution, it isn't able to dissolve as much.
So cooling it can cause the substance to fall out of solution aka precipitate.

Normally, if ever, you can't get it all out of solution, but you can often get significant amounts out.

Agent MadHatter - 22-8-2009 at 20:50

Well right now its at room temp. but not evaporating. I can't heat it or it will isomerize and freezing wouldn't help since there is already some crystals in the bottom, just not what I want.


kclo4 - 22-8-2009 at 20:56

Tell us about the compounds present and we can possibly help you out more...

separate the solution from the unwanted crystals and then cool it off?

Surely evaporating it over crystals that you do not want will be a mistake!

Agent MadHatter - 22-8-2009 at 20:59

I'm trying to get calcium tartarate from cream of tartar and HCL.

I have Tartaric acid, CaCL2, and KC1. I need to evap the HCL/Water solution so I can use a solvent to get CaCL2

kclo4 - 22-8-2009 at 21:06

I'm a bit confused.

What is in the solution, and I assume it is calcium tartrate that has already precipitated?

The solubility of, according to wiki, is insignificant at 0*C, I bet it doesn't rise much with temperature either.


Agent MadHatter - 22-8-2009 at 21:30

Yeah. But the book I'm reading says to evap the HCL solution because it contains some salts in it. I really am trying to follow the book to a T since thats how my professor will want me to do it.

Thats why I wanted to evap it. I'm not going to do anything with CaCL2, just throw it out. But I still want to get it.

Its the journey that counts.

kclo4 - 22-8-2009 at 22:01

Oh I see.
well, if it says evaporate it, I guess that is what you've got to do..

What is the solvent you are going to use to extract the calcium chloride? I'd assume something like an alcohol?

crazyboy - 23-8-2009 at 04:30

The element chlorine is Cl, capital "C" then lowercase "l" not a 1 and not a capital "L" and yes it does make a difference. We know what you are talking about but as you have written it you are evaporating a material which does not exist.

Agent MadHatter - 23-8-2009 at 14:23

My bad, that was just a typo. I meant CaCl.