Sciencemadness Discussion Board - Synthesis of Solid Calcium Hypochlorite

Synthesis of Solid Calcium Hypochlorite

mewrox99 - 13-7-2010 at 20:24

Hello.

I would like to make some solid calcium hypochlorite to seen how good of an oxidant it is (in the pyro sense)

I have heard that it is made from passing Cl2 into calcium hydroxide.

Is it aqueous or solid and how to I get a semi-pure dry powder.

Thank you

mnick12 - 13-7-2010 at 20:35

Well,
You can buy 54% CaOCl at the pool store as pool shock.
I dont think you will have any luck trying to make solid calcium hypochlorite, it is sensitive to CO2 in the air and is very likely to decompose into chlorate and chloride during isolation from a solution. You are better off buying the impure stuff at the pool store.

mewrox99 - 13-7-2010 at 20:45

Yeah I'm just a bit short on cash right now (I can only find 10kg amounts which are expensive)

Any way to make crude calcium hypochlorite?

I've always been interested in it's oxidizing power and would love to see how it would react with metallic powders and sugar.

All I've seen is a bunch of retards mixing there parent's pool chlorine and some IpOH in a plastic bottle. On the topic of that what products are formed. Acetone?

rrkss - 13-7-2010 at 21:14

Quote: Originally posted by mewrox99

All I've seen is a bunch of retards mixing there parent's pool chlorine and some IpOH in a plastic bottle. On the topic of that what products are formed. Acetone?

The first product formed will be acetone. However because acetone is a methyl ketone, the acidic hydrogens on the carbon alpha to the carbonyl will be one by one replaced by chlorine. Then the the the trichloromethyl group will be cleaved giving chloroform and the ketone will be oxidized to the carboxylate forming calcium acetate.

Look up the haloform reaction.

Picric-A - 14-7-2010 at 02:05

Industrially calcium hypochlorite is made by passing chlorine into a Ca(OH)2 slurry then drying.
the production of CaCl2 is inevitable and you will always get traced of Ca(OH)2 and CaCO3 left.

peach - 14-7-2010 at 02:30

rrkks is correct, the old sk00l method of producing chloroform was by the haloform reaction, which mixed acetone and hypochlorite (either bleach solution or calcium bleaching powder).

JohnWW - 14-7-2010 at 03:49

The industrial-grade solid bleach and disinfectant made by passing Cl2 gas into a Ca(OH)2 ("slaked lime") slurry, then drying, is called "chloride of lime". Besides Ca(OCl)2, it is liable to contain some CaCl2 (due to the formation of HCl as a byproduct); and, if an excess of Cl2 is not used, unreacted Ca(OH)2 and carbonate and bicarbonate.

mewrox99 - 14-7-2010 at 06:38

Seems Easy enough I'll give it a try tomorrow.

Should I make a desiccator bag and dry with NaOH since it doesn't like CO2 in the air

The WiZard is In - 14-7-2010 at 06:59

Quote: Originally posted by mewrox99

Hello.

I would like to make some solid calcium hypochlorite to seen how good of an oxidant it is (in the pyro sense)

Emphasis added.

Brake fluid.

mewrox99 - 14-7-2010 at 18:23

No not the 13 year old making crude bottle 'bomb' sort of pyro.

Wanna see out of curiosity what it'll be in flash powders and see If I can do a sugar burn reaction.

I find the novel oxidizers quite interesting. Wanna see if I can make some flash with the periodate of a cobalt-amine complex

densest - 14-7-2010 at 18:58

@mewrox99 - put on your safety glasses, face shield, and don't hold anything in your hands. This way lies some very unpredictable stuff... and choking fumes.

CaCl2 is very hygroscopic! So mixing any oxidizer contaminated with it with a metal powder is asking for a reaction very soon - a very unpredictable time. Milliseconds? Seconds? Minutes? Be sure it'll be at the most inconvenient time possible!

This is also the reason for the relatively few pyrotechnic oxidizers in general use. Most of the others are hygroscopic or contain enough water of crystallization or are acidic/basic enough to initiate a reaction at room temperature. The challenge is finding a system which is stable enough to make and keep and then set it off!

You might have fun with what Shimizu calls "negative oxidizers": sulfates, etc. which are decomposed by magnesium or aluminum. Read his books - he knows what he's talking about. Remember that CuO + Al is a very powerful flash and quite sensitive... there are a lot of combinations which could surprise you.

mewrox99 - 14-7-2010 at 21:27

Oh yes I have heard of the infamous CuO/Al explosive 'thermite'

I have played around with Sulfate as an oxidant with Al and Mg a while ago but the inhalation of Sulfur oxides was less than fun.

Thanks for the warning of the instability of the mixtures. I will only test sub 200mg amounts. Oxohalo salts have always fascinated me.

At school I begged my teacher to let my try some Mg/KIO3, he let me and I was quite disappointed.

Has anyone messed with chlorites, they seem quite interesting.

Formatik - 14-7-2010 at 21:56

Quote: Originally posted by mewrox99

I've always been interested in it's oxidizing power and would love to see how it would react with metallic powders and sugar.

Those kinds of mixtures are very unstable, especially with sugar. Hypochlorite mixtures are even easily worse than permanganates. Not hard to see considering facts like NaClO.7H2O attacking organics like paper, etc. under carbonization and liberation of chlorine oxides. Chlorinated lime mixtures with significant hypochlorite content can also be shock sensitive.

Chlorites are only a bit better. Mixtures of alkali chlorites and sulfur are known to ignite by themselves. And are also quite sensitive. A very small amount stabilized NaClO2 solid mixed with some sulfur flowers, burns rapidly with a bluish fireball when exposed to a burning match.

Quote:

All I've seen is a bunch of retards mixing there parent's pool chlorine and some IpOH in a plastic bottle. On the topic of that what products are formed. Acetone?

This might form chloroformic isopropyl hypochlorite, if the alcohol is anhydrous.

mewrox99 - 15-7-2010 at 00:23

They were most probably using 70% IpOH.

It seems to release alot of Cl2 and that fills the bottle producing a pressure explosion.

Also on the topic NaClO.7H2O crystalline NaClO exists!. I thought sodium hypochlorite only existed in solution.

franklyn - 18-7-2010 at 07:28

Calcium Hypochlorite in the form of " Bleaching Powder " is produced by passing
Chlorine gas over slaked lime. The reaction of solid Lime hydrate and Chlorine
leads to the formation of a mixture of dibasic Calcium Hypochlorite and basic
Calcium Chloride, at up to 40 % conversion of the available Calcium Hydroxide.
it is not hygroscopic, but decomposes in water and alcohol.
5 Ca(OH)2 + 2 Cl2 => Ca(OCl)2 • 2 Ca(OH)2 + CaCl2 • Ca(OH)2 • H2O + H2O

On further chlorination, hemibasic Calcium Hypochlorite Ca(OCl)2 • 1/2 Ca(OH)2,
and neutral Calcium Chloride hydrate are formed until 60 % of the available
Calcium Hydroxide has been converted , containing up to 37 % available chlorine.
Available Chlorine is always less due to formation of Chloride salt.
10 Ca(OH)2 + 6 Cl2 => Ca(OCl)2 • 2 Ca(OH)2 + CaCl2 • Ca(OH)2 • H2O +
2 Ca(OCl)2 • 1/2 Ca(OH)2 + 2 CaCl2 • H2O + 3 H2O

Concentrated Calcium Hypochlorite also known as HTH ( High Test Hypochlorite )
is made by including lye to speed production.
3 Cl2 + 2 NaOH + 2 Ca(OH)2 => Ca(ClO)2 + CaCl2 + 2 NaCl + 2 H2O
After drying the precipitate , this product will range from ~ 50 % to over 70 %
of actual Calcium Hypochlorite.

Rosco Bodine provided this useful resource on Hypochlorites
http://www.sciencemadness.org/talk/files.php?pid=97172&a...

dann2 provided this reference
Chlorine Oxides and Chlorine Oxygen Acids
http://www.sciencemadness.org/talk/files.php?pid=121766&...

US patents , 1767048 , 3950499 , 4367209 , 4504457 , 20090008603

Chlorine & chlorine products
http://books.google.com/books/download/Chlorine___chlorine_p...

Attachment: Hypochlorite Ca(ClO)2 forms of.pdf (219kB)
This file has been downloaded 856 times

"404 not found" - Chlorine & Chlorine Products

JohnWW - 18-7-2010 at 09:19

Quote: Originally posted by franklyn

(cut)
Chlorine & chlorine products
http://books.google.com/books/download/Chlorine___chlorine_p...

This, and variants of it, gives "404 not found". It could be that the whole site http://books.google.com has crashed or gone down, but if anyone has this PDF, please upload it here.

franklyn - 19-7-2010 at 04:37

JohnWW you always seem to encounter issues with access ,
Here it is at the top of the list , perhaps you can acces it from here.
http://www.google.com/search?q=Chlorine+%26+chlorine+product...

Alternatively it is available from archive.org
In * pdf ~ 3 MB
http://ia331435.us.archive.org/3/items/chlorinechlorin00clou...
In * djvu ~ 5 MB
http://ia331435.us.archive.org/3/items/chlorinechlorin00clou...

.

Sedit - 19-7-2010 at 05:59

Quote: Originally posted by rrkss

Quote: Originally posted by mewrox99

All I've seen is a bunch of retards mixing there parent's pool chlorine and some IpOH in a plastic bottle. On the topic of that what products are formed. Acetone?

I was under the impression that in this reaction the hypochlorite was forming an organic hypochlorite where are known to be dangerously explosive hence the fireballs seen you the boobtub videos. Useful substances since they can convert Toulene into BnCl quickly and easy but they always seemed like a rough way to go about it.

Formatik - 19-7-2010 at 10:09

I've only heared of organic hypochlorites forming alongside chloroform if the alcohol was absolute, and the hypochlorite solid.

Not sure if aqueous alcohol and solid hypochlorite also form it in small amounts.

Aqueous hypochlorite and alcohol will get the chloroform and other stuff.

Primary and secondary alkyl hypochlorites are annoyingly unstable and tend to crackle away spontaneously, which transfers into explosion if there is a trigger like being exposed to sunlight (maybe strong light too), maybe materials like rubber, etc. Noxious ill smelling compounds too.

Picric-A - 19-7-2010 at 11:25

Alkyl hypochlorites are not dangerous/explosive if made in a controlled manner as described in the attached patent.

They can be very useful as organic oxidisers or can be used to make pure sample of inorganic hypochlorites (free form any chlorides, hydroxides ect...) by reaction with hydroxides, eg;
Sodium hydroxide + isopropyl hypochlorite --> Sodium hypochlorite + isopropyl alcohol

Attachment: HYPOCHLOROUS ACID AND THE ALKYL HYPOCHLORITES.pdf (618kB)
This file has been downloaded 763 times

mewrox99 - 20-7-2010 at 01:19

But wouldn't the sodium hypochlorite react with the isoproyl alcohol?