Sciencemadness Discussion Board

Making potassium Hypochlorite?

XeonTheMGPony - 7-8-2017 at 19:01

Is it the same for NaClO?

Bubbling chlorine gas though sodium hydroxide solution that's cold so would potassium the same? just bubble Chlorine gas through chilled potassium hydroxide?

I work with NiChrom allot, and I been wanting to get chromium and nickel it then occurred to me to just dissolve all my waste (Nichrome) in Muriatic (HCl) acid as I have lots and here it is cheaper then dirt!

So did that and worked great, followed extractions & Ire video with the carbonate (Didn't work at first but then I figured to concentrated added water and all good)

Last stage is the oxidization with calcium hypochlorite, but I want potassium dichromate so need to use potassium hypochlorite.

So atme I have 2L with 36.2grams of Nickel chromium cabonate suspended in it atm.

[Edited on 8-8-2017 by XeonTheMGPony]

XeonTheMGPony - 7-8-2017 at 19:09

ok guess it is after a bit of research online (Tired so not thinking to clearly)

if mods want this thread can be dumped if not will post updates on the dichromate project here.


ave369 - 7-8-2017 at 22:17

Yes, making potassium hypochlorite is no different from making sodium hypochlorite. You can't get it in solid form, unlike sodium hypochlorite, but the solution can be prepared exactly the same way.

symboom - 7-8-2017 at 22:30

Wait what I think you got calcium hypochlorite which is solid and sodium hypochlorite mistyped. speaking of potassium carbonate or potassium sulfate and calcium hypochlorite should give you a really concentrated solution of potassium hypochlorite and a percipitate of calcium carbonate or calcium sulfate

[Edited on 8-8-2017 by symboom]

woelen - 7-8-2017 at 23:19

Quote: Originally posted by ave369  
Yes, making potassium hypochlorite is no different from making sodium hypochlorite. You can't get it in solid form, unlike sodium hypochlorite, but the solution can be prepared exactly the same way.
How stable is solid sodium hypochlorite? I never managed to make this. I allowed concentrated bleach (12.5% active chlorine) to evaporate to dryness, but the dry material does not contain any hypochlorite anymore. If an acid is added to the dry solid, then a deep yellow color is obtained and no bubbling of chlorine gas, indicating a mix of chlorate and chloride. Probably most is chloride with a little chlorate in it as well.

I have read somewhere about the existence of a pentahydrate of sodium hypochlorite, but this decomposes at room temperature.

JJay - 8-8-2017 at 00:10

You can make potassium hypochlorite by electrolyzing a potassium chloride solution or reacting potassium hydroxide solution with chlorine, but it's essential to keep the temperature low to avoid auto-oxidation to potassium chlorate. Of course, you probably know this.

You can also use potassium carbonate or potassium sulfate to precipitate calcium from chromate and dichromate solutions.

XeonTheMGPony - 8-8-2017 at 03:46

Ya I know the ElectroChemical method but was thinking of the chlorine injection method as the most expedient for this project and I do have Potassium Hydroxide, but with a clearer mind thinking be a shame to use it on this project so think I'll butcher some batteries and electrolyze it. KOH is some what pricy here, but atm I at least have an easy OTC source so need to debate it a bit internaly.

SymBoom: Oh I have tons of Calcium Hypochlorite; Sodium hypochlorite but what I want is Potassium hypochlorite as this makes the target product easier to get to, ie potassium Dichromate, Guess I should have saved that potassium sulfate from last run of nitric acid!

ave369 - 8-8-2017 at 06:35

Quote: Originally posted by woelen  

I have read somewhere about the existence of a pentahydrate of sodium hypochlorite, but this decomposes at room temperature.


That's what I meant (http://www.sciencedirect.com/science/article/pii/S0040402016...). Potassium hypochlorite does not allow for even that.

[Edited on 8-8-2017 by ave369]

symboom - 8-8-2017 at 07:01

That is interesting solid sodium hypochlorite never seen that.
The alkali group follows patterns which means lithium hypochlorite can be isolated as a solid. Sodium hypochlorite greenish-yellow solid (pentahydrate). For cheapest method electrolysis of potassium chloride 30 pound bag of sodium free water softener or more expensive no salt substitute. electricity being the cost factor. For fastest calcium hypochlorite and potassium sulfate.

Potassium chloride and calcium dichromate double displacement potassium dichromate percipitating out.
Potassium dichromate 4.9 g/100 mL at 0C

Calcium chromate
16.3 g/100mL (20 °C)
The dichromate being extremely soluble

Calcium Dichromate, CaCr2O7, may be obtained by treating a solution of the chromate with sulphuric acid, filtering off the calcium sulphate, and concentrating. Treatment of the neutral chromate with chromic acid, or partial saturation of calcium carbonate with chromic acid, also gives the dichromate as silky yellowish-brown crystals. Both a tetrahydrate, CaCr2O7.4H2O, as yellowish-red prisms, and a tri-hydrate, CaCr2O7.3H2O, forming deliquescent red crystals, are known. It is fairly soluble in water.

Potassium chromate
62.9 g/100 mL (20 °C)

Side note If mixed with boron and ignited, calcium chromate will burn violently.


[Edited on 8-8-2017 by symboom]

[Edited on 8-8-2017 by symboom]

woelen - 8-8-2017 at 07:19

Quote: Originally posted by ave369  
That's what I meant (http://www.sciencedirect.com/science/article/pii/S0040402016...). Potassium hypochlorite does not allow for even that.

[Edited on 8-8-2017 by ave369]

Very interesting. I'll see whether I can buy a pound or 2 of this interesting chemical. It puts hypochlorite on steroids, must be really cool for AJKOER :D

But seriously, this indeed is a very interesting thing and if this is commercially available as a lab chemical, then it must be stable on normal storage. I really wonder where this material can be purchased. Making it in an amateur setting most likely is very difficult, otherwise it would be available for a much longer time. It is a novelty reactant, which only is available since very recently

AJKOER - 8-8-2017 at 08:16

To prepare KClO, I would try freezing a concentrated mix of K2SO4 and NaClO forming a precipitate of Na2SO4.7H2O leaving KClO.

The K2SO4 can be sourced as a precipitate from freezing a mix of KCl and MgSO4.
---------------------

At the expense of a piece of glassware (attacked), I learned that a slurry of Ag2O will react with NaCl (or KCl) forming a white precipitate of AgCl and aqueous NaOH (or correspondingly, KOH). Likely reactions:

Ag2O + H2O = 2 AgOH

AgOH + KCl = AgCl(s) + KOH

Treating cold dilute KOH with Cl2 forms KCl and KClO, as noted above.

If one adds Ag2O/AgOH, to NaClO, the reported product is AgCl precipitate and AgClO3. In other words, the silver hypochlorite disproportionates to the insoluble chloride and chlorate.

[Edited on 8-8-2017 by AJKOER]

XeonTheMGPony - 8-8-2017 at 12:11

Extraction and ire did it just by reacting it with calcium hypochlorite to get Calcium Chromate, Now I was suspecting the displacement reaction may have worked, so will see if that works as I have potassium chloride and potassium hydroxide.

Goal is to make a Nickle and Chromium electroplating baths.

S.C. Wack - 8-8-2017 at 14:08

I wonder why OS (2-naphthoic acid) adds some KOH with the carbonate to the HTH. They don't comment on purity (1937), but don't much want any Ca in solution.

AJKOER - 8-8-2017 at 15:16

With respect to NaOCl.5H2O, be careful what you mix it with or intentional attempts to dehydrate.

For example, any compound that removes the water from the hydrate may leave, per my readings, unstable (explosive?) solid NaOCl, or the reaction may proceed dangerously.

Per one source (see, https://pubchem.ncbi.nlm.nih.gov/compound/sodium_hypochlorit... ), to quote:

"Decomposition
The anhydrous solid obtained by dessication of the /sodium hypochlorite/ pentahydrate will decomp violently on heating or friction.
Bretherick, L. Handbook of Reactive Chemical Hazards. 4th ed. Boston, MA: Butterworth-Heinemann Ltd., 1990, p. 984"

Another source (see https://www.atsdr.cdc.gov/MMG/MMG.asp?id=927&tid=84 ,
), to quote:

"Anhydrous sodium hypochlorite is very explosive."

My warning of the possible nature of this compound has been made previously on other forums, as well,. Please see, for example, http://www.scienceforums.net/topic/16795-dried-bleach-crysta... .]

[Edited on 9-8-2017 by AJKOER]

AvBaeyer - 8-8-2017 at 18:14

There is a detailed prep of potassium hypochlorite solution in Organic Syntheses. It uses potassium carbonate and calcium hypochlorite. It is in one of the Notes for a synthesis. I do not have the exact reference at hand but you should be able to find it easily with a web search.

AvB