weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
Potassium Hypochlorite?
I was thinking about new ways to make potassium chlorate (the
bleach+KCl method gave virtually no yield and even the other method (Na2CO3+Ca(ClO)2====2NaClO+CaCO3, filter, heat, then treatment with KCl gave a
very low, impure yield. So I took equal amounts of calcium hypochlorite and potassium sulfate (I had nothing to measure, or weigh the chemicals) and
added a lot of water to the flask containing the two. It gave me a green solution, in addition to the calcium sulfate precipate, that won't go away
even when heated. But this website says that potassium hypochlorite is a colourless solution (http://www.cameochemicals.noaa.gov/chemical/4315)
The solution had the typical characteristics of hypochlorites, weakening a cloth that I filtered it with to such an extent that it ripped apart
easily. And when I heated it. a white powder remained at the bottom. I added some water to the powder so that it did not all dissolve. and puts it in
the freezer. After a while I took it out, filtered it and washed the filtering paper in a flask. I got a white solution with still undissolved powder.
So, is that potassium chlorate? It certainly is less soluble than I thought if it is. Also, if the green solution is potassium hypochlorite, then what
is the contaminant that made it that colour? Maybe contaminants in the potassium sulfate that I used?
|
|
|
stygian
Hazard to Others
Posts: 242
Registered: 19-9-2004
Member Is Offline
Mood: No Mood
|
|
free chlorine? sodium hypo soln. is green as well you know.
|
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
Yes, but if it was free chlorine, then the green colour would go away once I have heated it. But even when I have heated it for over 30 minutes, the
green colour still persists. And a solution of sodium hypochlorite that I made using sodium carbonate and calcium hypochlorite is colourless,
sometimes a very light pink.
|
|
|
phlogiston
International Hazard
Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
How green is it?
What are your sources for the sodium hypochlorite and potassium sulfate / what contaminants are likely to be in them?
| Quote: | | sodium hypo soln. is green as well you know. |
A pure NaClO solution is colorless where I live.
[Edited on 14-1-2012 by phlogiston]
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
Calcium hypochlorite was from pool shop and potassium sulfate was a fertilizer. I didn't think they'll be too pure, but the resulting white powder I
got from boiling the solution, freezing and filtering looks pure enough, but it wasn't very soluble in water.
|
|
|
UnintentionalChaos
International Hazard
Posts: 1454
Registered: 9-12-2006
Location: Mars
Member Is Offline
Mood: Nucleophilic
|
|
Hypochlorite solutions are usually yellow green. I prepared some 12% NaOCl from chlorine gas and clean NaOH and the solution was quite green. Upon
adding a large excess of NaOH, it became more yellowy, but retained a fairly strong color.
Bleach (which is pale green-yellow) is completely decolorized after the haloform reaction, which consumes the hypochlorite.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
|
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
But the solution was much much more green than bleach. It was more green than a bottle of chlorine gas in the air. Also, the green colour didn't go
away until I boiled every last drop of water, but when I redissolved the powder, then filtered it, the powder on the filtering paper was dissolved in
water to make a translucent,
slightly white solution. The filtered out solution was colourless. So, if the green was hypochlorite, wouldn't it have decomposed by the time the
solution has been heated to half its volume? But if it wasn't, then why didn't the green colour come back when I redissolved the powder?
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
If you are interested in some other possibly "better" paths to Chlorate formation see the recent thread below and some of the cited references.
http://www.sciencemadness.org/talk/viewthread.php?tid=18452
I am currently looking at paths via Magnesium hypochlorite (add MgSO4, Epsom's salt, to bleach, NaClO), to which one adds HOCl (a must for Chlorate
formation in the reputedly superior non-alkaline approach) and an acid (to lower pH in 5.5 range) and warm the solution (around 70 C) and not boil.
Alternately, aqueous suspension of Magnesium hydroxide (or hypochlorite) and treat with Cl2 (or, Chlorine water which is basically, HCl and HOCl) and
warm. Add KCl and then cool to precipitate KClO3.
The thread focuses on ZnO with ostensibly higher yields, but Epsom's salt presents an easy path to Magnesium hypochlorite. See the reference below for
comments on Mg(ClO3)2 route.
Source: "The Manufacture of Sulphuric Acid and Alkali: Ammonia-soda, various ..." by Georg Lunge, an online googlebook. To quote from page 669:
"4. Magnesia Bleach-Liquor.
This can be made by decomposing a solution of bleachingpowder with Epsom salts and decanting from the gypsum formed. It has been proposed for
bleaching by Claussen, and again by Ramsay; it is said to bleach more rapidly, and not to turn straw, flax, hemp, etc., brown, as it is free from
lime; but it suffers decomposition more quickly than chloride of lime. The separated magnesia does not at all injure the fabrics (Bolley and Jokisch,
Schwciz. polyt. Zeit., 1866, p. 120). Such a liquor was patented by Oliver Grantham, Sinnock, and Leverson (B. P. 2351 of 1861), without adding
anything new. F. Hodges has shown that a liquor of the same kind (prepared from ordinary bleaching-powder and kieserite) can bleach linen fabrics
without exposure on grass, if they have previously been steeped in a hot solution of sodium carbonate.
Balard prepared a bleaching-liquor by dissolving magnesia in aqueous hypochlorous acid; Grouvelle by passing chlorine into magnesia suspended in
water.
None of these solutions had been properly investigated until Lunge and Landolt (Chem. Ind., 1855, p. 340) undertook this task. They tried first to
prepare a bleaching-magnesia, analogous to bleaching-powder, by treating solid magnesium hydroxide with chlorine, either in the dry or in the moist
state; but they did not obtain anything fit for use, viz., a. mass with only 0-15 available and 4-3 chloride-chlorine.
Now chlorine was passed into a milk of- magnesium hydroxide and water, at temperatures between o° and 100°. Even at 0°, together with magnesium
hypochlorite, much chlorate was formed, more than corresponding to half of the chlorine entering into the reaction. At 15° a little more chlorate was
formed, together with much hypochlorate, some of which was changed into chloride, with evolution of oxygen. In both solutions the hypochlorite is
easily converted into chlorate, not merely by heating to 50°, but even by prolonged agitation by a current of air at ordinary temperatures. At 70°
C, from the first mostly chlorate was formed, with a little chloride, produced by loss of oxygen. Hence magnesium hypochlorite in statu noscendi does
not possess much stability and is easily transformed into chlorate.
Very different from this is the behaviour of a product obtained by decomposing a solution of bleaching-powder with magnesium sulphate. Here no
conversion of hypochlorite into chlorate occurs, a very slight production of MgCl2 by loss of oxygen is observed, but no splitting off of free HOCl.
The stability of this bleaching-solution is almost equal to that of bleaching-powder solutions. Kept in closed vessels in the dark, it had lost only
1/60 of its available chlorine after keeping for thirty-three days; kept open in the dark, no change was observed after six days, and after
thirty-three days a loss of not quite 1/5 of bleaching-power. Kept in closed bottles in diffused daylight, the stability of this solution was superior
to that of all other bleach-liquors; after thirty-three days 9/10 of the available chlorine was still present. This is therefore a very good
bleaching-solution, if kept from the light.
M'Clelland and Lange (B. P. 27463 of 1907) render this solution more stable by adding during its preparation magnesium oxide, hydroxide, or carbonate,
stirring them properly in by means of an ebonite rod with india-rubber flaps, or allowing the liquor to trickle through the above-quoted magnesium
compounds."
LINK:
http://books.google.com/books?id=FnrTAAAAMAAJ&pg=PA670&a...
[Edited on 15-1-2012 by AJKOER]
|
|
|
Pulverulescent
National Hazard
Posts: 793
Registered: 31-1-2008
Member Is Offline
Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!
|
|
| Quote: | | I was thinking about new ways to make potassium chlorate (the bleach+KCl method gave virtually no yield) |
The boiling of household bleach to 'prepare chlorates' of any kind is so close to being futile it barely deserves comment . . . 
This forum is littered with threads containing instructions on such simple methods of preparing chlorates and perchlorates by electrolysis that just
about anyone with a grain of commitment should be able to follow them! 
Why not have a look around the forum or just UTFSE!
P
|
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
Quote: Originally posted by Pulverulescent  | | Quote: | | I was thinking about new ways to make potassium chlorate (the bleach+KCl method gave virtually no yield) |
The boiling of household bleach to 'prepare chlorates' of any kind is so close to being futile it barely deserves comment . . .
This forum is littered with threads containing instructions on such simple methods of preparing chlorates and perchlorates by electrolysis that just
about anyone with a grain of commitment should be able to follow them!
Why not have a look around the forum or just UTFSE!
P |
I looked around the forum, and all the methods involves either chlorine gas or hypochlorous acid, and it's not very convenient for me to bubble
chlorine gas through various solutions. After all, the only thing I've got for bubbling chlorine gas is a plastic bottle with tubing. I would think
that this method involving potassium sulfate would be a lot less dangerous and a lot more convenient to me.
|
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
| Quote: Originally posted by AJKOER | If you are interested in some other possibly "better" paths to Chlorate formation see the recent thread below and some of the cited references.
http://www.sciencemadness.org/talk/viewthread.php?tid=18452
I am currently looking at paths via Magnesium hypochlorite (add MgSO4, Epsom's salt, to bleach, NaClO), to which one adds HOCl (a must for Chlorate
formation in the reputedly superior non-alkaline approach) and an acid (to lower pH in 5.5 range) and warm the solution (around 70 C) and not boil.
Alternately, aqueous suspension of Magnesium hydroxide (or hypochlorite) and treat with Cl2 (or, Chlorine water which is basically, HCl and HOCl) and
warm. Add KCl and then cool to precipitate KClO3.
The thread focuses on ZnO with ostensibly higher yields, but Epsom's salt presents an easy path to Magnesium hypochlorite. See the reference below for
comments on Mg(ClO3)2 route.
Source: "The Manufacture of Sulphuric Acid and Alkali: Ammonia-soda, various ..." by Georg Lunge, an online googlebook. To quote from page 669:
"4. Magnesia Bleach-Liquor.
This can be made by decomposing a solution of bleachingpowder with Epsom salts and decanting from the gypsum formed. It has been proposed for
bleaching by Claussen, and again by Ramsay; it is said to bleach more rapidly, and not to turn straw, flax, hemp, etc., brown, as it is free from
lime; but it suffers decomposition more quickly than chloride of lime. The separated magnesia does not at all injure the fabrics (Bolley and Jokisch,
Schwciz. polyt. Zeit., 1866, p. 120). Such a liquor was patented by Oliver Grantham, Sinnock, and Leverson (B. P. 2351 of 1861), without adding
anything new. F. Hodges has shown that a liquor of the same kind (prepared from ordinary bleaching-powder and kieserite) can bleach linen fabrics
without exposure on grass, if they have previously been steeped in a hot solution of sodium carbonate.
Balard prepared a bleaching-liquor by dissolving magnesia in aqueous hypochlorous acid; Grouvelle by passing chlorine into magnesia suspended in
water.
None of these solutions had been properly investigated until Lunge and Landolt (Chem. Ind., 1855, p. 340) undertook this task. They tried first to
prepare a bleaching-magnesia, analogous to bleaching-powder, by treating solid magnesium hydroxide with chlorine, either in the dry or in the moist
state; but they did not obtain anything fit for use, viz., a. mass with only 0-15 available and 4-3 chloride-chlorine.
Now chlorine was passed into a milk of- magnesium hydroxide and water, at temperatures between o° and 100°. Even at 0°, together with magnesium
hypochlorite, much chlorate was formed, more than corresponding to half of the chlorine entering into the reaction. At 15° a little more chlorate was
formed, together with much hypochlorate, some of which was changed into chloride, with evolution of oxygen. In both solutions the hypochlorite is
easily converted into chlorate, not merely by heating to 50°, but even by prolonged agitation by a current of air at ordinary temperatures. At 70°
C, from the first mostly chlorate was formed, with a little chloride, produced by loss of oxygen. Hence magnesium hypochlorite in statu noscendi does
not possess much stability and is easily transformed into chlorate.
Very different from this is the behaviour of a product obtained by decomposing a solution of bleaching-powder with magnesium sulphate. Here no
conversion of hypochlorite into chlorate occurs, a very slight production of MgCl2 by loss of oxygen is observed, but no splitting off of free HOCl.
The stability of this bleaching-solution is almost equal to that of bleaching-powder solutions. Kept in closed vessels in the dark, it had lost only
1/60 of its available chlorine after keeping for thirty-three days; kept open in the dark, no change was observed after six days, and after
thirty-three days a loss of not quite 1/5 of bleaching-power. Kept in closed bottles in diffused daylight, the stability of this solution was superior
to that of all other bleach-liquors; after thirty-three days 9/10 of the available chlorine was still present. This is therefore a very good
bleaching-solution, if kept from the light.
M'Clelland and Lange (B. P. 27463 of 1907) render this solution more stable by adding during its preparation magnesium oxide, hydroxide, or carbonate,
stirring them properly in by means of an ebonite rod with india-rubber flaps, or allowing the liquor to trickle through the above-quoted magnesium
compounds."
LINK:
http://books.google.com/books?id=FnrTAAAAMAAJ&pg=PA670&a...
[Edited on 15-1-2012 by AJKOER] |
I don't know how to make HOCl apart from bubbling chlorine gas through water (inconvenient and dangerous) or immediately adding sodium carbonate to a
bubbling solution of calcium hypochlorite/vinegar ( there is a LOT of contaminations in the hypochlorous acid produced.) But, I'll have a look around
the forum and I guess UTFSE.
|
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
I searched, and the methods to make hypochlorous acid involves either the addition of a very dilute acid to a hypochlorite salt or bubbling dichlorine
monoxide through water. Making dichlorine monoxide requires chlorine gas, and it's just too hard to keep the hypochlorous acid stable while trying to
crystallize the salt formed so it doesn't ruin the reaction. It might be easy with proper equipment, but the only glasswares I've got is a beaker, a
syringe, two flasks and a broken test tube. So I'm going with the most convenient method for me, and the yields are not bad (about 30-40 grams of
potassium chlorate.
I might try it for just academic purposes, but not my most favoured ways of making potassium chlorate (or any chlorates)
[Edited on 16-1-2012 by weiming1998]
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
A simple way to create and react Chlorine/Chlorine Water is to place a Cl2 generator inside an inverted dome with the solution to be treated at the
base of the dome. That is, a small Cl2 generator bottle is placed inside a larger inverted one. Be careful to perform this reaction outside as there
may be escaping Chlorine gas, and protective eye ware is advised as Cl2 can very quickly irritate the eyes.
You can make a dome by cutting off the bottom of a large plastic bottle, but I will leave it to others to design simple home made equipment
themselves.
Chlorine can be easily generated by adding pH Down (for Spa), which is NaHSO4, to NaClO. The reaction starts very slowly, but can be become quite
vigorous in Cl2 evolution.
Another approach for Cl2 creation (I have not tried this one), involves substituting CaCl2 (Calcium Chloride) for NaHSO4 (or any strong mineral acid)
and adding to Bleach (do conform with local laws). If you have Ca(OCl)2, just add CO2 + H2O (Seltzer water).
As the reaction temperatures are below 100 C, you don't even need a heat source (use a hot water bath).
Also, the process is 3 steps. Create the Chlorate (from the Cl2 water reaction on Mg(OH)2 or Mg(ClO)2 and adding mild heat 70 C), next add KCl, and
then cool to precipitate the KClO3.
|
|
|
Pulverulescent
National Hazard
Posts: 793
Registered: 31-1-2008
Member Is Offline
Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!
|
|
Alan Yates' great site; the perfect place to start! ( )
P
|
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
| Quote: Originally posted by AJKOER | A simple way to create and react Chlorine/Chlorine Water is to place a Cl2 generator inside an inverted dome with the solution to be treated at the
base of the dome. That is, a small Cl2 generator bottle is placed inside a larger inverted one. Be careful to perform this reaction outside as there
may be escaping Chlorine gas, and protective eye ware is advised as Cl2 can very quickly irritate the eyes.
You can make a dome by cutting off the bottom of a large plastic bottle, but I will leave it to others to design simple home made equipment
themselves.
Chlorine can be easily generated by adding pH Down (for Spa), which is NaHSO4, to NaClO. The reaction starts very slowly, but can be become quite
vigorous in Cl2 evolution.
Another approach for Cl2 creation (I have not tried this one), involves substituting CaCl2 (Calcium Chloride) for NaHSO4 (or any strong mineral acid)
and adding to Bleach (do conform with local laws). If you have Ca(OCl)2, just add CO2 + H2O (Seltzer water).
As the reaction temperatures are below 100 C, you don't even need a heat source (use a hot water bath).
Also, the process is 3 steps. Create the Chlorate (from the Cl2 water reaction on Mg(OH)2 or Mg(ClO)2 and adding mild heat 70 C), next add KCl, and
then cool to precipitate the KClO3. |
Yes, I might try that. I've never thought of a dome before. Previous attempts on bubbling chlorine gas through water was done by a plastic tubing in a
closed container. The reaction that was generating the chlorine was calcium hypochlorite+sodium bisulfate. The chlorine was coming out of the
container, and I have to tie a wet cloth around my nose and mouth to stop it from poisoning me, even though I did it outside.
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
