Sciencemadness Discussion Board

Suggestions for using up sodium hypochlorite solution

Sulaiman - 19-12-2024 at 07:37

I planned to revisit the haloform reaction
bleach + acetone = chloroform + sodium hydroxide + sodium acetate

I tried years ago with cheap supermarket bleach
- most of my product was lost in solution

Then I cleverly tried with 30% (or 35%, I can't remember) NaOCl solution
- Wow ! That was more exothermic than I expected,
- no product collected.

So, preparing for next year, I thought 100 ml of chloroform would be a good target.
So I bought 3 litres of 10% sodium hypochlorite solution,
(just nice for my 5l rbf and heating mantle)
enough to ensure excess when combined with 100ml acetone for a theoretical yield of 108ml chloroform.
Simple.
,.....................
Strangely, via my favourite online consumer shopping site
I can buy 1.5 litres of chloroform for less than the cost of making 100ml
(A 4 litre can is about USD12 incl p&p etc.)
....................
Other than typical household and medical uses,
what chemistry would 3 litres of 10% sodium hypochlorite solution be useful for ?

[Edited on 19-12-2024 by Sulaiman]

Boffis - 19-12-2024 at 08:28

Hi Sulaiman, I usually use up excess bleach to prepare chloroform but as you have done this already you could try making potassium chlorate or recover chromates from chrome hydroxide. Then there is the preparation of potassium bromate, 2-naphthalene carboxylic acid from "orange crystals" or pyrazine carboxylic acid from "pop-corn pyrazine", nitrostilbenes from nitrotoluenes and I am sure there are others on the SM web site.

Axt - 19-12-2024 at 08:38

Few days ago I mixed piperazine dichloride https://www.compspoultry.com.au/product/piperizine-100-g/ with it. immediate precipitate of ClN(C2H4)2NCl, It'll go bang if you hit it with a hammer.

[Edited on 19-12-2024 by Axt]

Thanks

Sulaiman - 19-12-2024 at 08:44

I should have looked/thought/researched more - I will
Of those mentioned I fancy trying chlorate production as that may have some (fun) uses and I definitely want to re-visit electrochemistry.
I buy sodium chlorate for about USD1.5/kg incl.p&p so it would not be for cost benefit.
I'll let this idea float around somewhere in the recesses of what is left of my mind.

@Axt: that sounds fun.
Unfortunately no pyrotechnics for me for at least a year :(

[Edited on 19-12-2024 by Sulaiman]

DraconicAcid - 19-12-2024 at 09:00

Quote: Originally posted by Boffis  
...2-naphthalene carboxylic acid from "orange crystals" ...

Wait, what's this one?

Boffis - 19-12-2024 at 11:18

Hi DraconicAcid, "orange crystals" are 2-naphthyl methyl ketone and are available from suppliers of perfumary and flavouring ingredients. When dispersed into warm bleach it rapidly dissolves to form the sodium salt of 2-naphthoic acid and chloroform altough I have never managed to recover the latter. It is less tempremental than acetylpyrazine under these conditions.

DraconicAcid - 19-12-2024 at 11:55

Ah. I thought you were making it from the artificial colours in Tang.

woelen - 19-12-2024 at 12:01

Another nice experiment is making organic hypochlorites with your bleach. The process is very simple. Never make more than a few tenths of ml at once!

Mix some hypochlorite solution with a weak acid. Acetic acid will do, H3BO3 also is fine.
To this mix, add a little methanol. This produces a colorless gas, CH3OCl. Light the gas. It does BOOM! Really impressive.
Only do this experiment with a few drops of methanol!

A somewhat safer experiment is adding propylalcohol instead of methanol. A yellow liquid will separate. Isopropylalcohol also works, but the isopropyl ester is less stable and may explode.
The liquid propylester of hypochloric acid burns extremely well, with a dark sooty flame. These are just fun experiments, do not create amounts, larger than a few tenths of a ml! The stuff is increadibly sensitive and you may have explosions, especially in warmer climate!

The vapors of organic hypochlorite esters are also quite annoying when you breathe them, they are irritating like NH3 or SO2, but with a different smell. They are quite toxic, in the sense of being corrosive for wet tissue.

[Edited on 19-12-24 by woelen]

Keras - 19-12-2024 at 12:32

You can also use it for Hoffman rearrangements and probably mild oxidations, such as benzyl alcohol to benzaldehyde. You can also make Cr (VI) compounds from Cr (III) with hypochlorite. I’m sure you can do a lot of other things.

[EDIT: neutralise cyanide.]

[Edited on 19-12-2024 by Keras]

Fery - 19-12-2024 at 12:41

I recently did the chloroform reaction with 1-acetonaphthone as a substrate which I prepared some time ago by Friedel-Crafts acylation of naphthalene in CH2Cl2 solvent at reaction temperature below +20 C. The recent chloroform reaction was a biphasic system unlike reaction with acetone which dissolves in water. The T of the chloroform reaction with 1-acetylnaphthalene had to be 60-80 C for 1 hour and very rapid magnetic stirring was necessary to increase the reaction surface. There was a chloroform scent from the top of condenser but at the end all the chloroform hydrolyzed to Na formate and the scent vanished. 2-fold molar ratio of NaOH had to be used to the substrate and 3-fold molar ratio of NaOCl (well even more NaOCl as it has to be in an excess and the unreacted NaOCl destroyed with little of acetone at the end, also some NaOCl was lost due to disproportionation reaction into NaClO3 at elevated T).
The complete reaction was:
C10H7-CO-CH3 + 3 NaOCl + 2 NaOH -> C10H7COONa + HCOONa + 3 NaCl + 2 H2O
It could explain why somone obtains almost no chloroform, it is partly soluble in water and may hydrolyze in excess of NaOH at elevated temperature. The reaction with acetone needs to be at as lowest temperature as possible to minimize hydrolysis of the chloroform with NaOH which is produced in the reaction:
CH3-CO-CH3 + 3 NaOCl -> CH3COONa + HCCl3 + 2 NaOH
So take in mind whether the substrate is water miscible or not.
2-acetylnaphthalene is more thermodynamically stable than 1- isomer and is prepared by Friedel-Crafts acylation of naphthalene at elevated temperature (in refluxing nitrobenzene solvent instead of cold T and CH2Cl2 solvent for 1- isomer).
Some time ago I got very poor yield from another substrate benzylideneacetone -> cinnamic acid which was caused by insufficiently low temperature. Benzylideneacetone melts at 40 C, but I did the reaction unhappily at too low temperature due to lack of knowledge at that time.
From pinacolone you can obtain pivalic acid which ester with phenethyl alcohol has the commercial name Centifolyl which is very likely derived from latin name Rosa Centifolia.

[Edited on 19-12-2024 by Fery]

Texium - 19-12-2024 at 15:15

Quote: Originally posted by woelen  
Another nice experiment is making organic hypochlorites with your bleach. The process is very simple. Never make more than a few tenths of ml at once!
t-butyl hypochlorite is stable enough to make tens of mL at once, and is a useful reagent for certain organic chlorinations and oxidations: http://www.orgsyn.org/demo.aspx?prep=cv5p0184

I’d still rather not store it though, even though they say you can.

DraconicAcid - 19-12-2024 at 15:28

Quote: Originally posted by Texium  
t-butyl hypochlorite is stable enough to make tens of mL at once, and is a useful reagent for certain organic chlorinations and oxidations: http://www.orgsyn.org/demo.aspx?prep=cv5p0184

I’d still rather not store it though, even though they say you can.


I once had a prof named Tanner, who spoke of t-butyl hypoiodite as if he'd invented the reagent (don't know if he did). He told us of a student who had an ampule of it, and thought it looked cloudy. He held it up to the window to get a better look, and it dramatically photolyzed.