| Pages:
1
..
4
5
6 |
Keras
National Hazard
Posts: 896
Registered: 20-8-2018
Location: (48, 2)
Member Is Online
|
|
Then again, if you have some, you can make more by generating sulphur trioxide and dissolving it into your stash to make oleum that you can then
dilute to get 100% acid
|
|
|
clearly_not_atara
International Hazard
Posts: 2787
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
Quote: Originally posted by woelen  | | You can still buy 15% acid, cheaply (e.g. 25 liters of it for 50 euros or so). It can easily be boiled down to 70% or even 80%. Boiling it down to
90+% however is harder. |
I never saw the problem with commercial acid being 15% or 50% because it's only the part above 80% that is actually hard to dehydrate. But I wondered
anyway: can you just evaporate water from sulfuric acid? Can you avoid boiling?
According to Hornung and Giauque (attached), the vapor pressure of water above H2SO4*4H2O (about 58%) at 25 C is 4.795 mmHg = 0.64 kPa, while the
vapor pressure of pure water at 25 C is 3.16 kPa. So, at a relative humidity of less than 20%, H2SO4 will spontaneously concentrate all of the way to
58%!
That's not too likely, but even at a more realistic 50%-or-so humidity you should be able to get significant evaporation by just letting a bowl of the
stuff sit in the sun. If you go from 15% to 30% you've reduced the solution by nearly half. And that means a lot less volume in the boiling flask and
electricity consumed in the process.
Attachment: hornung1955.pdf (369kB)
This file has been downloaded 317 times
|
|
|
learningChem
Hazard to Others
Posts: 182
Registered: 21-7-2011
Member Is Offline
Mood: No Mood
|
|
Yes, you can concentrate H2SO4 and it's an interesting exercise in amateur chemistry, but the point is that having concentrated acid is now a 'crime'.
I just came accross this video https://www.youtube.com/watch?v=-J-6C6IhfIU
"How I’m dealing with the sulfuric acid ban "
Before watching I thought it was about workarounds for the 'ban' but the guy is actually destroying the acid he has at home. And that's how people who
'obey the law' are supposed to behave. So, no more concentrated sulfuric for amateurs.
|
|
|
karolus28
Hazard to Self
Posts: 51
Registered: 14-4-2019
Location: EU's Brazil
Member Is Offline
Mood: zgrzyt
|
|
Just a reminder that in Poland sulfuric acid drain cleaners are still available even online
Hi, please read about exif data.
|
|
|
Hexabromobenzene
Hazard to Others
Posts: 122
Registered: 27-4-2021
Member Is Offline
|
|
I was experimenting with the evaporation of a solution of sulfuric acid. I used an old cat litter box with an area of about 0.2 square meters.
The initial concentration of sulfuric acid is about 25%. Evaporation time 1.5 months. The temperature in the heated room is 24 degrees. This happened
in winter with temperatures in the open air down to -20 degrees Celsius (average -10)
Final acid concentration about 50% (density 1.5)
If you heat the container, you can probably evaporate sulfuric acid up to 70%. Heating cables are well suited as a heater for a plastic polypropylene
container.
Evaporation of strong solutions of salts or acids is an extremely long process. Trying on a container with heating will allow you to reduce its area
and reduce the evaporation time, as well as increase the theoretical evaporation limit.
P.S Initial volume acid was 3-3.5 liter. Final volume 1 liter
[Edited on 23-6-2022 by Hexabromobenzene]
|
|
|
Fyndium
International Hazard
Posts: 1192
Registered: 12-7-2020
Location: Not in USA
Member Is Offline
|
|
| Quote: Originally posted by learningChem | | Well, looks like amateur chemistry is finished in the so called 'european union'. Also, I find it rather funny that this forum has a lot of people
willing to make excuses for tyranny. Then again, I guess unchecked political power is well aligned with reductionist materialism. And no, none of
these measures are about protecting a very small number of people from 'acid attacks'. |
Same goes with private gun ownership.
However, I'm not excusing tyranny. I exclusively stated that by making obtaining things a bit more difficult so the average dumbass is deterred from
readily accessing it will already cut off most of the harm.
|
|
|
| Pages:
1
..
4
5
6 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
