Sciencemadness Discussion Board

Blue? Potassium chlorate/perchlorate?

budullewraagh - 2-9-2004 at 19:41

yesterday i decided to recover potassium chlorate/potassium perchlorate by adding match heads to boiling water, filtering out the recovered sulfur and cardboard and boiling off the water. well, i found that as i concentrated it, the mixture (that ended up as a solution/suspension of white powder) turned a certain light blue, as seen below. can anybody tell me what that blue is from?

potassium chlorate perchlorate.JPG - 517kB

The Ed - 2-9-2004 at 19:57

Well... what color were the matchheads? If you're trying to get chlorate from matchheads you need to use a pretty fine filter, otherwise unwanted crap is always gonna seep through. Is the blue a clearish blue or more opaque?

budullewraagh - 2-9-2004 at 20:14

the matchheads were white. click the link to see just how blue it is.

BromicAcid - 2-9-2004 at 20:35

Remember that match heads contain significant quantites of ground glass to help the abrasiveness of them. You had a boiling mix of oxidizers, anything come into contact with them that could have been oxidized, e.g., copper, nickel, stainless steel. These could have reacted and given you your blue color.

budullewraagh - 2-9-2004 at 20:41

ah right. that's a bloody shame. i had been doing it in my beaker which was sitting in a pot, but that took too long so i just poured the solution into the pot. still, i think the pot is stainless steel. i dont think iron has any ions that look blue, does it?

BromicAcid - 2-9-2004 at 20:45

Stainless usually contains appreciable chromium and nickel which could have colored the reaction mixture, also I was thinking along the lines of a copper bottomed pan but you didn't mention that.

Do some qualitative analysis on it, I would lay money on it being a metal cation. Copper and nickel of course spring first to mind.

The Ed - 2-9-2004 at 21:07

Since there's a chance it's chromium or nickel compounds, be careful with that crap. Salts of those metals are fairly toxic.

Proteios - 2-9-2004 at 23:03

Quote:
Originally posted by The Ed
Since there's a chance it's chromium or nickel compounds, be careful with that crap. Salts of those metals are fairly toxic.


Chuckle......

BromicAcid - 3-9-2004 at 06:31

Chuckle? Although I don't treat nickel salts with as much respect as they deserve either, they do happen to be somewhat decent carcinogens.....

budullewraagh - 3-9-2004 at 07:00

lovely. now that you mention it, the bottom is copper and the blue i suppose is from aqueous nickel and chromium ions. that's a shame. next time i do this i'll use less water to dissolve the match heads.

thanks for your help

[Edited on 3-9-2004 by budullewraagh]

budullewraagh - 3-9-2004 at 12:18

actually come to think of it...the iron should oxidize first. and there are no blue ions of chromium, iron or nickel

budullewraagh - 3-9-2004 at 14:43

i tried it again in a glass beaker and got the blue. it must be a dye in the match head that turns it white, but is blue.

hodges - 3-9-2004 at 15:14

You can test for metal ions by adding a base such as NaOH to a solution and seeing if there is any precipitate. No precipitate would more likely indicate an organic dye. Another test would be to add a strong acid and see if the color changes. Many organic dyes can act as indicators given extreme pH levels.

budullewraagh - 3-9-2004 at 16:59

it's a dye

budullewraagh - 5-9-2004 at 16:33

i just did this again and used a few red match heads with the white ones, which, i just realized is not necessarily a good thing. the solution is now red, so i don't believe the red is red phosphorus, but it could easily kill me if it is. do you think it is red p?

budullewraagh - 5-9-2004 at 16:56

and i came up with this...what is the white? sulfur or chlorate? (84 match heads in 100mL H2O strained with tissue paper twice)

potassium chlorate pink.JPG - 46kB

BromicAcid - 6-9-2004 at 06:47

The red color is a dye to my experience. The left over solid contains a high percentage of glass powder but is also chlorate/perchlorate. The sulfur usually boils to the top like you mentioned before and is definitely yellow, mine came off rubbery like the rubberized sulfur from running 250C or greater molten sulfur into cool water.

When I did this though I used about 3,000 match heads in a 2 liter pan. The whole bottom of the pan was covered with a paste of chlorate/perchlorate/glass about 4 cm deep when the mixture was at full boil. Never analyzed the mixture though, at least you didn't try and dissolve the match heads in HCl like I did :(

(Red phosphorus is not incredibly toxic, well, unless you boil it in basified water.)

budullewraagh - 6-9-2004 at 07:03

i don't understand how you got that problem with HCl.

KClO3+HCl->ClO2??



anyway, you think i'm safe with distilling the brew i made?

BromicAcid - 6-9-2004 at 07:07

Distilling? What kind of condensate are you hoping to collect, or do you just mean evaporating to dryness? If that is the case don't evaporate totally to dryness, I made that mistake before as well.

You can go to my web page and look at both the HCl incident and evaporating to dryness, both of these fall into my mistakes category.

And yes, that is the equation for what happended and caused the explosion.

budullewraagh - 6-9-2004 at 08:04

yeah, i intend to boil off the water and end up with a bunch of white powder and a little solution in my beaker.

could you help me with the exact equation complete with charges?

budullewraagh - 6-9-2004 at 08:06

also, last i checked, potassium chlorate decomposed to yield O2, which isn't so bad. i had some of mine decompose a few days ago when doing the same experiment, but it didn't blow up. perhaps when you did it you still had some sulfur?

potassium chlorate or perchlorate(blue??)

STING - 8-9-2004 at 07:22

hi folks, to the ? of potassium chlorate or perchlorate---> he said he cut off the match heads"right" well what about the blue dye in the paper stick, u know that is dark blue paper stick?? get my drift...


Edit: No need to create a new thread, I assume you did this by accident and confused the New Reply with the New Topic button....

[Edited on 8-9-2004 by chemoleo]

Quince - 4-2-2005 at 04:10

I'm having some trouble with the search function. Searching for chlorate gives too many results, and just about all are regarding either use of chlorates, or synthesis using electrolysis. I'm trying to find NON-electrolytic synthesis procedures for either sodium or potassium chlorate.

BTW, I assume there's no problem if Half-Salt (sold as table salt that is half sodium/half potassium chloride) being used in electrolytic synthesis?

The electrolysis should be simple but..

chloric1 - 4-2-2005 at 09:23

Basically if you want chlorate you need at least 5 V and the 3 to 4 amps if you want a few grams the same day you started!

As far as Non-electrolytic synthesis goes, you could bubble chlorine gas through hot concentrated alkali and separate by fractional crystalization. Chlorates are fairly cheap and you can even find them on ebay. I would not really bother with making them unless you want the learning experience. Now Perchlorates are a little harder to get but I read an older J. Am Chem. article about repeated evaporation of potassium chlorate with 70% nitric acid gives 30% yield. The rest is potassium nitrate so no need to waste anything.:D

[Edited on 2/4/2005 by chloric1]

[Edited on 2/4/2005 by chloric1]

FrankRizzo - 4-2-2005 at 11:14

I'm sure this has been mentioned before, but an old AT or ATX (with dummy load) computer power supply makes a nice source for 3.3/5/7/12V DC current, and can usually be had for quite cheap.

Potassium chloride can be found in the hardware store as water softener salt for people worried about sodium affecting their health.

Carbon gauging rods are sold at the welding supply shop for ~$0.50, and make decent electrodes for this type of operation if the copper is stripped off first.

vimal - 5-2-2005 at 07:44

i think i had studied somewhere that:
ClO2 dimerizes to give a red colour solution. so could it be it? :)

nice pictures!

aludel - 5-2-2005 at 12:43

Quote:
Originally posted by BromicAcid

When I did this though I used about 3,000 match heads in a 2 liter pan. The whole bottom of the pan was covered with a paste of chlorate/perchlorate/glass about 4 cm deep when the mixture was at full boil. Never analyzed the mixture though, at least you didn't try and dissolve the match heads in HCl like I did :(

(Red phosphorus is not incredibly toxic, well, unless you boil it in basified water.)



The red phosphorus is usually on the match box' sides, not in the match heads... it probably depends on the brand.
I once scraped a bit off, gently heated in a tube pre-filled with CO2 and got a bit of white P which condensed as tiny drops on the cold areas.
It's too much hassle to get useful quantities but at least I got a glimpse of white P. (the smell... the glowing in the dark... it's >20 years ago but I still remember!)

If the match heads are red, it could be dichromate.

Palladium as anode!

SAM4CH - 31-3-2005 at 06:10

Can I use Palladium as anode for electrolysis if KCl,NaCl in making Chlorate and perchlorate!?