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uchiacon
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So, should I just get the Pt anode for chlorate and perchlorate?
Can't find a MMO anode that isn't too small or too expensive...
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hissingnoise
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That's a question you'll have to answer yourself, IMO, but try to get *all* the facts first. . .
To start with, you could check out prior threads on perchlorates and the various anodes used by others!
IIRC, there's an old, good long thread on PbO2 anodes that might help; UTFSE!
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uchiacon
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Except for the fact I don't have the chemicals to make a lead dioxide anode and dont want to have to deal with lead compounds. They are nasty. I got
about 20 pages(for about 2 hours) through that thread before it went on a tangent of shit that didn't concern me.
Don't try and tell me to UTFSE, the info(Pt vs MMO) isn't there. UTFBrain nextime.
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hissingnoise
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Uchiacon, the "F" in UTFSE stands for forum, not fucking---you can unknot your knickers. . .
No route to perchlorate is hassle-free but lead dioxide is a cheap and effective method which requires reagents, thought and effort.
Failing that, you *can* buy NH4ClO4. . .
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uchiacon
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You are completely missing what I'm wanting to do here...
I just want an opinion of whether I should buy Pt or MMO(and try to make PbO2 anodes for chlorate) for moderate chlorate and light perchlorate
production lol.
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hissingnoise
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I'd go for Pt/Ir alloy; expensive wire but virtually trouble-free---Pt-plate has a habit of eroding in amateur cells and the rest disintegrate to
varying degrees over time.
The last time I wanted perchlorate I ordered NaClO4 from a local pharmacist; I had it in three days but it wasn't exactly cheap. . .
It probably depends on your level of commitment!
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watson.fawkes
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News to me. No, really. And the way it seems to be intoned
(albeit in text form), it seems to practically mean the latter almost always.
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uchiacon
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So just get an MMO/Ti setup for chlorate off ebay and some Pt/Ir wire for perchlorate ?
Something like http://cgi.ebay.com/Platinum-Iridium-20-002-wire-x-5-Five-Fe...
and just coil it around a cathode for perchlorate?
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hissingnoise
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That wire is verrry thin uchiacon--- .002" is about .05mm. . .
The electrical conductivity of Pt/Ir is only moderate and a strand of this wire would be subject to unacceptable resistive heating at even
low-amperage currents.
The minimum "convenient" thickness, I'd say, would be around .5mm.
If you were to purchase this wire, you would need to form your anode as a ribbon, comprising many strands, each of which would need a secure
electrical connection.
It's doable but fiddly---if you were adventurous you could perhaps weave the wire into the form of a mat, effecting a connection by thick copper or
brass strips holding the anode in a vise-type arrangement. . .
Do not use *ferrous metals* in the connections as iron can quite easily contaminate platinum surfaces.
It's also well to remember that along with adding corrosion resistance, iridium hardens platinum, making it somewhat brittle. . .
[Edited on 11-7-2009 by hissingnoise]
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chloric1
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Some areas, ammonium perchlorate is still available. An equal mix of nitric and hydrochloric acid will convert this to perchloric acid on
evaporation. Heating AP with alkali and alkaline carbonated furnished ANHYDROUS perchlorates!
Believe it or not, the chlorine in the acid mix is not responsible for the destruction of ammonium, its the nitrous acid! That is why you use equal
portions of HNO3 and HCl instead of the normal aqua regia methods.
Fellow molecular manipulator
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uchiacon
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This is the Pt mesh I'll be buying for chlorate and perchlorate synthesis. I cant be fucked buying different anodes. The Pt plating is 2.54 microns
thick, and I'm getting 20 square inches of it for $100USD. There'll be 2 seperate Pt anodes for chlorate and perchlorate.
www.anometproducts.com//App_Themes/anometproducts/PtCladNb_M...
Comments?
[Edited on 04-07-09 by uchiacon]
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hissingnoise
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It probably comes down to personal preferences, but I'd stick with graphite for chlorate. . .
In my day, I used gouging rods but found that there were two grades of gouging rod.
One type disintegrated quickly producing a black electrolyte which when allowed to settle left a foggy white viscous solution---I assumed the anode
had been made from graphitic powder compressed with some kind of water-soluble polymer.
The other type eroded slowly even at high temperature and on settling left a clear solution.
Chlorate was isolated by decantation and evaporation; I used two cells with the one anode/cathode arrangement.
I'd use the platinised anode only where it's essential. . .
[Edited on 12-7-2009 by hissingnoise]
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appetsbud
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just a quick question that im sure has been answered before but is long since buried in the sciencemadness vaults, as im sure someone will be able to
answer this painlessly.
im just wondering what the safety issues are with the electricity. i plan on doing the electrolysis with a 4amp power supply (old laptop charger) with
something like 10V .
obviously im not planning on touching the naked wires whilst running, but i was just interested about the potential danger... death? wikipedia tells
me that 100mA can kill, which is substantially less than my 4A, making it seem pretty clear.
i just wanted to get a heads up from others who have done this in the past and precautions, if any regarding the power, that are needed to be taken.
just a simple 'stay well back when running and turn off the power supply with a broomstick before approaching', or more?
just before anyone thinks to concern themselves with enlightening me to the chemical dangers im fairly confident in that area, practical
electro-chemistry is a little new to me.
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hissingnoise
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Quote: Originally posted by appetsbud  | Im just wondering what the safety issues are with the electricity. i plan on doing the electrolysis with a 4amp power supply (old laptop charger) with
something like 10V .obviously im not planning on touching the naked wires whilst running, but i was just interested about the potential danger...
death? wikipedia tells me that 100mA can kill, which is substantially less than my 4A, making it seem pretty clear.
just a simple 'stay well back when running and turn off the power supply with a broomstick before approaching', or more? |
OK, I've got my composure back!
Thanks appetsbud; I think I can say without the slightest fear of contradiction that 4A @ 10V won't kill you!
With DC you can grasp both bare wires tightly and not know they're actually carrying current.
The voltage would need to be quite a bit higher to cause noticable shock.
How much higher is a good question but below 30V there's little to worry about.
Mains voltage here is 220V and that voltage can be dangerous.
The combination of high current and voltage is very dangerous.
It's probably better not to touch any bare wires anyway but the real voltage will be in the primary windings if they're mains-fed.
(It was the broomstick bit that caused me to pepper my keyboard and screen with explosively expelled hamburger). . .
Now for the cleanup!
[Edited on 21-7-2009 by hissingnoise]
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appetsbud
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luckily for me you managed to edit your post before i could witness the horrific flaming (i presume) that mine instigated ...
yeah, sorry about the broomstick thing, it was meant to be a bit tongue in cheek. i was trying to exemplify my lack of knowledge about electrical
safety by alluding back to the videos you (or at least i) got shown in lower school years about the 'horrors of electricity' or whatever... im sure
you'll appreciate my over cautious approach was probably the most fitting given my lack of knowledge on the subject, and the veil of mystique that
seems to enshroud the subject somewhat.
thanks for clearing that up, i dont really have many people i can ask directly, and the only ones that seemed to have answers were people who knew as
little as me but weren't afraid to relentlessly advocate their presumptions.
just managed to get some beautiful bubbles sprouting from my electrodes this morning after a little tinkering with my spatterings of physics knowhow,
just have to get a vent hole with tube and drop a flea in and i should be good to go.
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hissingnoise
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| Quote: Originally posted by appetsbud | | luckily for me you managed to edit your post before i could witness the horrific flaming (i presume) that mine instigated ... |
Indeed appetsbud, the unfortunate members who did witness it are now receiving counselling and will bear the scars. . .etc..
Trying to be serious---the broomstick bit conjured a slapstick image which hit the funny-bone, with laughter being the spice of life.
BTW, your electrolyte won't need stirring if the cathode reaches close to the bottom of the cell---hydrogen evolution will provide enough circulation
by itself. . .
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densest
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I hate to deflate the levity here.... but.... there's a reason that ground fault circuit interrupters trigger (depending on the local laws) at 5 mA or
so: 50 mA through the heart region can kill. Once past the insulating skin, the interior resistance of the human body ranges from 10 to 1000 ohms. In
the unfortunate event that one has a cut or one's hands are wet with a salt solution, it doesn't take a high voltage to kill if the current passes
across the chest (head to feet, hand to feet if you're unlucky, hand to hand). Anything over about 12 volts can be bad if you're
really unlucky. AC at 50 Hz is especially bad because it's close to the ideal frequency to disrupt the pacemaker centers in the heart
to cause fibrillation which is often fatal.
So - many of us have survived shocks from the mains or high powered electrical or electronic apparatus. That doesn't mean that one should be careless
if one has water and electricity in the same place. Insulating (rubber, plastic, etc) shoes (a 1Meg grounding conductor to prevent sparks is
not a hazard), and keep one hand in your pocket while fiddling with any electrodes which are supplied from a non-current-limited
source. Insulating gloves (not leather, plastic or rubber instead) can help, but if they have holes (sharp wires etc.) they are not effective.
In dry conditions without wounds you can get away with touching many high powered things. Chemistry often involves salt solutions which are highly
conductive and which will render your skin conductive. Pure water (11 Megohm, for instance) can be used as an insulator... but that's
no fun 
Under 12V it takes an incredible run of bad luck and ignorance to hurt yourself. Under 24V it's quite difficult but possible. SELV (safety extremely
low voltage) stops at 48VAC and current limiting is required to qualify as "safe". So anything involving a computer PSU, wall wart power supplies,
etc. is usually safe if you keep your hands dry.
I do know of an incident with 5VDC in which someone wore a gold wedding ring while working on live equipment. It shorted power to
ground (250 A or more) and got red hot. Very bad burns! So current limiting on any experimental supply is a good idea.
New safety regulations in the US require protection against molten metal splatter from accidental shorts while working on mains feeds capable of
serious high currents (1000 A or more at a guess).
I witnessed an incident in which a very experienced technician dropped a screw inside a high power (KW+) computer power supply. A transistor melted
with sufficient violence that a molten metal ball shot through the transistor case, through the computer case, and buried itself halfway through a 1/2
inch plate glass window. There were about 6 people in the same room - we were all lucky not to be in the trajectory!
Anyway, power limited supplies are the norm for easily available apparatus (except for microwave oven transformers) and are quite
useful for a lot of work.
[Edited on 27-9-2009 by densest]
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UnintentionalChaos
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| Quote: Originally posted by densest | I hate to deflate the levity here.... but.... there's a reason that ground fault circuit interrupters trigger (depending on the local laws) at 5 mA or
so: 50 mA through the heart region can kill. Once past the insulating skin, the interior resistance of the human body ranges from 10 to 1000 ohms. In
the unfortunate event that one has a cut or one's hands are wet with a salt solution, it doesn't take a high voltage to kill if the current passes
across the chest (head to feet, hand to feet if you're unlucky, hand to hand). Anything over about 12 volts can be bad if you're
really unlucky. AC at 50 Hz is especially bad because it's close to the ideal frequency to disrupt the pacemaker centers in the heart
to cause fibrillation which is often fatal.
So - many of us have survived shocks from the mains or high powered electrical or electronic apparatus. That doesn't mean that one should be careless
if one has water and electricity in the same place. Insulating (rubber, plastic, etc) shoes (a 1Meg grounding conductor to prevent sparks is
not a hazard, and keep one hand in your pocket while fiddling with any electrodes which are supplied from a non-current-limited
source. Insulating gloves (not leather, plastic or rubber instead) can help, but if they have holes (sharp wires etc.) they are not effective.
In dry conditions without wounds you can get away with touching many high powered things. Chemistry often involves salt solutions which are highly
conductive and which will render your skin conductive. Pure water (11 Megohm, for instance) can be used as an insulator... but that's
no fun :-)
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Where are you getting your pure water? It's more like 18Megaohm in our labs 
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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densest
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I can only afford second-hand water from surplus dealers and luck on labx and ebay!  Someday, if one of my inventions works & sells, maybe I can afford a deionizer to go after my reverse osmosis unit 
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VladimirLem
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nevermind...
[Edited on 2-7-2011 by VladimirLem]
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