Sciencemadness Discussion Board

New here, with a couple of questions on acids, Golden Rain and apparatus

artemov - 25-8-2018 at 21:23

Hi all, I'm new here and new to amateur chemistry as well. I'm trying to start off with some simple experiments and I have a couple of queries.

Coming from a place where many chemicals are very restricted, I have no access to sulphuric (battery acid by itself is not for sale, no rooto or whatever cleaners too), nitric (none in any form), and hydrochloric acid (as mosaic cleaners of unknown concentration with surfactants mixed in). Staying in an apartment block, I do not have access to a fumehood, no "outside/outdoors" either.

I do not have a distillation set, yet.
Currently I have 500g of oxalic acid, 500g of soap making lye and 100g of potassium iodide. I should be able to get the usual fertilizer/hydroponics grade salts like calcium nitrate (not sure if it is calcium ammonium nitrate instead ... how to test?), calcium sulphate, magnesium sulphate, ...

Acids
The first thing I want to do is to make some sulphuric and nitric acid, being tremendously useful and near ubiquitous in many experiments, using calcium sulphate and calcium nitrate respectively with oxalic acid as per this thread.
Should I mix them dry and gently heat until they dissolve in their water of crystallization? Make solutions of both or one of them and mix? Stoichiometric amount or one in access?
According to the attached file below, oxalic acid is in solution and slight excess, while calcium sulphate is sprinkled in.
In the case of making sulphuric acid, wouldn't excess near-insoluble calcium sulphate makes more sense as we can always filter the excess off along with calcium oxalate giving us very pure sulphuric acid?
In the case of nitric acid, I do agree using oxalic acid in slight excess would make sure that all the calcium nitrate are displaced, though yielding slightly contaminated nitric acid. Can I just boil the nitric acid in an open beaker to 68% azeotrope and remove the excess oxalic acid as well? Cheers.

Attachment: chemicals_sulfuric_acid_preparation_from_oxalic_acid_thompson1849.pdf (209kB)
This file has been downloaded 371 times

artemov - 25-8-2018 at 21:53

Golden Rain
If I manage to make nitric acid, use an excess of very small lead shots (0.2-0.5g each), hopefully pure, to make lead nitrate in solution, filter away any solids, add slight excess of potassium iodide directly to filtrate.
Either that, or use vinegar and 3% hydrogen peroxide to make lead acetate in solution ...

Heat, cool, and seal the beautiful golden solutions in 10ml glass vials for posterity and gifts.

Silicon/rubber tubings
It seems many glasswares have 10mm connections for tubings.
For example this and this.

Would a tubing with 6mm ID fit? Like this one.

Are silicon tubings suitable for vacuum distillation/filtration and for channeling gases like Cl2, NO2 and HCI?

fusso - 25-8-2018 at 22:10

If you have access to Ca nitrate then you can heat to decompose it to NO2 and dissolve NO2 in water to make dilute HNO3. This HNO3 will be purer than using oxalic acid.

Alkoholvergiftung - 26-8-2018 at 00:16

If you have no Access to nitrate you can also oxidize Ammoniumsulfate with MnO2 in deluted sulfuricacid the HNO3 will destill over.
8MnO2 +(NH4)2SO4 +7 H2SO4 = 8MnSO4 +2 HNO3 + 10 H2O
you can recycle the H2SO4 and the MnO2 with electrolysis. ;).
But you have no access to sulfuric acid if i were you i would make it from oxalic acid and gyps or magnesiumsulfate or electrolytical from this salts with an clay pott as diaphragma.


[Edited on 26-8-2018 by Alkoholvergiftung]

fusso - 26-8-2018 at 08:25

Quote: Originally posted by Alkoholvergiftung  
If you have no Access to nitrate you can also oxidize Ammoniumsulfate with MnO2 in deluted sulfuricacid the HNO3 will destill over.
8MnO2 +(NH4)2SO4 +7 H2SO4 = 8MnSO4 +2 HNO3 + 10 H2O
you can recycle the H2SO4 and the MnO2 with electrolysis. ;).
But you have no access to sulfuric acid if i were you i would make it from oxalic acid and gyps or magnesiumsulfate or electrolytical from this salts with an clay pott as diaphragma.
[Edited on 26-8-2018 by Alkoholvergiftung]
Where did you read about this reaction? I haven't heard of it before:o

Alkoholvergiftung - 26-8-2018 at 11:17

F.Kuhlmann wrote About " Comptes rendus, Nov. 1846, Nr. 22."
There was another Artikel what other Metal Oxydes can be used from his Colleges. It s an good source. Instand of MnO2 you can use PbO2 too or potasiumdichromate and concentrat sulfuric Acid.BaO2 Should work also.


[Edited on 26-8-2018 by Alkoholvergiftung]

CRUSTY - 11-9-2018 at 12:18

Just so you know, the golden rain reaction does not always work as it does in the videos. If the conditions aren't perfect, you will end up with a very fine precipitate, which although a pretty yellow, will settle into a mushy lump on the bottom of your container. Getting it to crystallize in a desirable way can be tricky.

Also, this is just me, but I would not recommend storing H2SO4/HNO3, unless you're really confident about your means of storage. The fumes will destroy any rubber, paper, etc. I've stored it in lab-grade glass bottles with Teflon-coated polyethylene caps, and that's really the only place I'm comfortable storing it. The solution will pretty quickly lose concentration when not properly sealed, and will lose its useful nitration properties with it. And if you decide, for whatever reason, that the stored solution isn't "worthy" of further use, it is very hard to dispose of. I'm talking hours of very slow reaction with sodium bicarbonate solution. Try to only prepare as much as you need for a given experiment.