Sciencemadness Discussion Board - Hydrochloric Acid from Toilet Cleaner

Hydrochloric Acid from Toilet Cleaner

Abromination - 17-7-2018 at 13:01

I know that many brands of toilet bowl cleaner contain about a 10% solution of hydrochloric acid. It is hard to get cheap HCl where I live, but I was wondering if I could just distill the HCl off from the toilet cleaner and leave all of the surfactants and
dyes behind. I know people do this with sulfuric acid from draim cleaner, but HCl exists as the gas hydrogen chloride. Would the water distil over with it to give me a solution or would I end up flooding my lab with hydrogen chloride gas?

DraconicAcid - 17-7-2018 at 13:17

The water should also distill over. That being said, it's always a good idea to make sure you have proper ventilation anyway.

JJay - 17-7-2018 at 13:51

The water and some HCl will distill over first, and the concentration will gradually increase to the azeotropic concentration. Once you reach the azeotropic concentration, the temperature and concentration will plateau.

You won't need any special ventilation unless you accidentally flash boil some HCl or let your condenser get hot, but good ventilation is a good idea anyway.

Cipher - 17-7-2018 at 14:10

And if you care more about safety than concentration, best to distill it into some water, so gas will more likely dissolve.
Hope you are ready to deal with back-flow if it will occur.

Abromination - 17-7-2018 at 14:34

I was planning on having some distilled water in the collection flask anyways. Ive heard of people doing similar things with formic acid from oven cleaner and flooding their labs with fumes so yes, safety over concentration.

happyfooddance - 17-7-2018 at 14:49

If your acid is under 20.2% by weight, there is a precisely 0.0% chance of suckback.

For safety, I would just do a titration (however crude) to make sure.

There is no reason to put water in the recieving flask.

Abromination - 17-7-2018 at 14:58

When I get a chance, I will do a titration. By weight the Lysol toilet cleaner I plan to use is supposed to be 12% by weight. I honestly am expecting it to be plus or minus 6%. Lucky for me, I don't need concentrated HCl.

CharlieA - 17-7-2018 at 15:43

Quote: Originally posted by happyfooddance

If your acid is under 20.2% by weight, there is a precisely 0.0% chance of suckback.

I must be missing something here; what is the relationship of composition to suckback?

happyfooddance - 17-7-2018 at 17:19

Quote: Originally posted by CharlieA

Quote: Originally posted by happyfooddance

If your acid is under 20.2% by weight, there is a precisely 0.0% chance of suckback.

I must be missing something here; what is the relationship of composition to suckback?

Suckback is caused by gases (like HCl) which are highly soluble in a liquid, and said gases being evolved at a slower rate than they are adsorbed, thus creating a vacuum.

But we are not talking about HCl(g), we are talking about aqueous HCl, which forms a maximum boiling (108.5°C) azeotrope with water that is 20.2% HCl by weight. If you boil a solution that is less than 20.2%, as JJay mentioned it will come over in a lower concentration than what is in the boiling pot until the concentration of the boiling pot reaches 20.2%. So unless you are distilling concentrated HCl there is no way to get HCl(g), hence no suckback.

Also, if he is distilling in a normal setup, not a bubbler, there is no possibility of suckback anyway... Just putting a little water in a recieving flask can never cause suckback.

Metacelsus - 17-7-2018 at 18:36

Toilet bowl cleaner often contains thickeners and surfactants, in addition to HCl. (Different brands may vary.) Distillation might cause a lot of foaming, so you should use an appropriately sized vessel.

Abromination - 17-7-2018 at 20:07

Quote: Originally posted by Metacelsus

Toilet bowl cleaner often contains thickeners and surfactants, in addition to HCl. (Different brands may vary.) Distillation might cause a lot of foaming, so you should use an appropriately sized vessel.

Good Idea. Strong stirring would be a good idea as well to keep foaming to a minimum. Would boiling stones be necessary?

happyfooddance - 18-7-2018 at 12:07

Quote: Originally posted by Abromination

Good Idea. Strong stirring would be a good idea as well to keep foaming to a minimum. Would boiling stones be necessary?

Boiling stones aren't necessary if you have decent stirring; however, a few small ones shouldn't hurt (as long as they don't interfere with the stirring).

Abromination - 18-7-2018 at 15:15

Boiling stones aren't necessary if you have decent stirring; however, a few small ones shouldn't hurt (as long as they don't interfere with the stirring).[/rquote]

Now that I think of it, the stir bar would act rather like a boilingstone itself. Also, you have a fair point. It would be difficult to use boiling stones with a stir bar.

VSEPR_VOID - 18-7-2018 at 16:20

I recommend buying some sodium bisulfate or sulfuric acid. Distilling a dry mixture of bisulfate, or concentration sulfuric acid, will yield hydrogen chloride. It would be much faster and cheaper than toilet bowl cleaning.

https://www.ebay.com/itm/Sodium-Bisulfate-NaHSO4-Minimum-of-...

https://www.ebay.com/itm/Pool-Breeze-Sodium-Bisulfate-Swimmi...

TesTube - 18-7-2018 at 18:11

Quote: Originally posted by VSEPR_VOID

I recommend buying some sodium bisulfate or sulfuric acid. Distilling a dry mixture of bisulfate, or concentration sulfuric acid, will yield hydrogen chloride. It would be much faster and cheaper than toilet bowl cleaning.

https://www.ebay.com/itm/Sodium-Bisulfate-NaHSO4-Minimum-of-...

https://www.ebay.com/itm/Pool-Breeze-Sodium-Bisulfate-Swimmi...

I think you forgot something

Abromination - 18-7-2018 at 23:10

[rquote I think you forgot something

[/rquote]

I agree