[Trizocy]

Hello, new guy here.

Im just wondering how hard is it to purify Hydrochloric Acid 30% up to 36-38%

Thanks

[Hunter2]

This is not recommended, because HCl is a gas dissolved in water.

[Trizocy]

Cant i vapor the water away then ?

[Hunter2]

The water will not go away the HCl gas will go away and HCl creates also an azeoptrope about 20% w.w.

http://www.akersolutions.com/Documents/PandC/Mining%20and%20metals/Hydrochloric%20Acid%20Concentration.pdf

[Trizocy]

So there is not simply way to purifty it?

[Hunter2]

No.

What impurities you will get rid off? HCl is cheap, easier to buy new one.

[Trizocy]

Well in my country the highest hcl u can buy is 30% (on the description it stand 25%-35%) if you want higher u need certificate/company/document to buy higher.
Importing hcl is also strict in my country, and have aldready try to ask many suppliers if they can send it to my country, which they say no to :/

Then my only way is to purify it :/

[mjc123]

Water is not an impurity in hydrochloric acid. Hydrochloric acid is a solution of HCl in water. Pure HCl is a gas. Even the 36% stuff contains 64% water.
Is the difference between 30% and 36% so crucial?

[Trizocy]

Yup between 36-38% is a MUST

But saw this video, https://www.youtube.com/watch?v=jv1Ms6Subg4, how pure do you think the Hydrochloric Acid be?
Anyone know how to speed this processes?

[mjc123]

You're not talking about purification, you're talking about concentration. He says the final product is 5 molar - well 36% HCl is 10 molar, so it's about half as concentrated, and considerably less concentrated than your 30%. He says it takes 2 weeks; I guess if he knew a way to make it faster he would have said.

[Babcock_Hall]

A standard way to purify hydrochloric acid is to distill it.  Constant boiling HCl is about 6.07 M IIRC.  This is what is used in hydrolysis of peptides, for example.  I realize that this might not be concentrated enough for your purposes.
http://pubs.acs.org/doi/abs/10.1021/ed012p377

[Trizocy]

Haha there goes my chemical skills 

That video is old, so maybe he found out a new way now?

Anyway so there is no simple way to concentration my Hydrochloric Acid?

[curiouscat]

Haha there goes my chemical skills 

That video is old, so maybe he found out a new way now?

Anyway so there is no simple way to concentration my Hydrochloric Acid?

One way, I'm speculating:

Generate HCl gas.
Have cold water in a container. Get it to equilibriate perhaps under a bit of pressure. I think you will reach 36%.

To generate the gas you could just mix  conc. H2SO4 & HCl in the right proportions. H2SO4 drives off the soluble HCl gas.

Or just heat your 30% HCl.

Alternatively try adding common salt & salt out the HCl gas from 30% HCl.

[Trizocy]

Can simple destilation work then?

[Babcock_Hall]

Can simple destilation work then?

That depends upon what you are trying to accomplish.  If you want to remove nonvolatile impurities, then distillation as I described it works fine.  If you need a high concentration, then what I described won't help.