Sciencemadness Discussion Board

Solidified Acids with Silica Gel

symboom - 27-1-2017 at 11:10

Another use for silica gel
https://en.m.wikipedia.org/wiki/Silica_sulfuric_acid

Ive done this experiment a bit hard to get the remaing acid
And it was really sticky like damp sand used drain cleaner could be the reason or maybe the absorbtion
SiO2–OH + HO–SO3H → SiO2–OSO3H + H2O (wiki states)
Water being evolved.
Psychological result:
The odd feeling when it is solidifying it felt safer to handle I guess the whole acids are liquid that burns skin not solids thinking mindset
Had to think to my self this is still sulfuric acid.

Always the less water the better dont want to waste the silica gel.

Also tried to solidify Hydrogen Peroxide
Some did decompose maybe due to nucleation points
I could be wrong less decomposes ehen chilled just above freezing point also my source was glow sticks I figure they have a higher percentage of Hydrogen Peroxide

Nitrogen dioxide absorbed on silica is next

Even nitric acid if concentrated enough might be worth a try

Maybe nitration mix sulfuric and nitric acids absorbed on silica gel could be possible.

Maybe even Hydrogen Chloride gas to make very concentrated Hydrochloric acid

[Edited on 27-1-2017 by symboom]

[Edited on 27-1-2017 by symboom]

Dan Vizine - 27-1-2017 at 19:23

The feeling of increased safety is no illusion, it is safer.

Acid burns by sulfuric acid follow the same rules as any other reaction. Intimate contact of the reactants is necessary for rapid reaction. Liquid acid achieves instant intimate contact. Granular solid acid achieves much less efficient contact.

Note that adsorption onto silica gel is a specialized process. Silica gel hydrates upon mixing. Sulfuric acid binds well. NO2 may react with the already-adsorbed water to give some adsorbed nitric acid, but the results will probably be mediocre. Hydrogen peroxide is doomed to failure. I imagine that hydrochloric acid with SiO2 will be similar to how it is with CaCl2. The HCL won't be bound.

hexahydrate - 16-6-2018 at 00:43

Quote: Originally posted by Dan Vizine  

Note that adsorption onto silica gel is a specialized process [...] Hydrogen peroxide is doomed to failure.


Looks like it is possible and it has been done.
Papers:

EDIT:
First link expired or was blocked, so I'm attaching this paper.


1. Silica xerogel–hydrogen peroxide composites: Their morphology, stability, and antimicrobial activity

2. Stabilization of hydrogen peroxide in silica gels

Attachment: Silica_xerogel_hydrogen_peroxide_composi.pdf (6.8MB)
This file has been downloaded 450 times

[Edited on 16-6-2018 by hexahydrate]

Ubya - 16-6-2018 at 08:29

could silica gel-sulphuric acid be used as the acid catalyst in a fisher esterification for example?

symboom - 16-6-2018 at 10:42

Fischer esterification or Fischer–Speier esterification is a special type of esterification by refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst
Such as isopropanol alcohol and acetic acid

Ubya - 16-6-2018 at 13:10

Quote: Originally posted by symboom  
Fischer esterification or Fischer–Speier esterification is a special type of esterification by refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst
Such as isopropanol alcohol and acetic acid


yes i know, it was an example of a reaction using an acid catalyst, usually sulphuric acid

symboom - 17-6-2018 at 11:32

I looked it up i didnot knoe and my post should have had more info i was going to say i dont see why not it should work
I appologize from my previous post

[Edited on 17-6-2018 by symboom]

[Edited on 18-6-2018 by symboom]