Sciencemadness Discussion Board

High quality NaClO3 using electrolysis?

x_blaster_x - 2-9-2015 at 11:27

By looking at this video:
http://www.youtube.com/watch?v=WEe_8hsc0f8

...that show how to made NaClO3, caught my attention this comment:

Clown Whisper
You can make this stuff by the pound through electrolysis using potassium chlorate directly > perchlorate. its real easy and more of a stable compound

You can get way better product. the stuff in this video is horribly impure. burs slow and yellow.
When you do this by way of electrochemistry is flashes and is violate/blue

...

Anyone have idea, how the mentioned electrolysis should work?

elementcollector1 - 2-9-2015 at 12:57

First of all, if it burns anything other than yellow, it's not sodium. Sodium's orange flame color tends to mask all other colors in concentrations as low as 1%. Second, burn time doesn't always depend on purity, though that does play a factor - without watching the video, I might be inclined to suspect particle size.

hyfalcon - 2-9-2015 at 17:39

That color in the flash usually indicates potassium instead of sodium.

Fantasma4500 - 3-9-2015 at 08:09

im puzzled... isnt chlorate usually made through electrolysis??

electrolysis is simply that you take 2 electrodes suitable for electrolysis (graphite mmo platinum), and run electricity through saltwater
sodium chloride giving sodium chlorate

i recall Dornier335A said that through careful and selective recrystallization, you can grow mono-crystals, which would be very high in purity, although seperating sodium chlorate from sodium chloride isnt that incredibly hard, and it gets many times easier with potassium chlorate, and yet easier with potassium perchlorate

for blasts and what not, maybe not counting in open air deflagrations and some incredibly few non-pyro chemical reactions purity wont mean that much to the overall use..

anyhow.. its not just sodium that gives yellow colour, carbon and many other impurities can give yellow colour.. nitrocellulose very obviously evidences you dont require sodium ions to get a yellow flash, sodium is oftenly seen as indication of general impurity

if you run careful electrolysis with an excess of sodium chloride present in the electrolysis cell, the sodium chlorate will be forced to deposit in crystals, seemingly not depending on temperature shifting back and forth, although its very possible impurities will gather in the crystal doing this, or just sodium chloride physically getting trapped inside the crystal

in short: dont worry about sodium chlorate purity, your uses of sodium chlorate will not suffer immensively

Aqua-regia - 4-9-2015 at 07:31

The anodic oxidation of chloride to chlorate needs small amount sodiumchromate, (inhibitor the catodic reduction of chlorate) reason the yellow solution . It is no problem the unchanged NaCl separate from chlorate. (perchlorate cannot detected if the temperatur of solution during the whole electrolysis is more than 70 celsius and right counted the Amper x time. For 4, 8 mol NaClO3 need appr. 885 Ah. The roughly efficiency of currency 80%

NaClO3 purification from NaCl and chromate:

dissolve14 g Ag2O in (basis 4,8 M starting NaCl), 250 ml fresh saturated chlorine -water solution, hold and mix in 60 celsius add further chlorine water still Cl can remaindly chlorine smell. Add to the NaClO3 solution, filter, add to the solution slight excess Ba(OH)2 solution, filter, the residue of Ba-ions, treated with diluted H2SO4, filter again, und you can evaporate your pour NaClO3, wash the crystals with 3 x 50 ml cold etOH.

Ag2O + Cl2 → AgClO + AgCl
3 AgClO → AgClO3 + AgCl
NaCl + AgClO3 → NaClO3 + AgCl

Ba2+ + 2 OH- + 2 Na+ + 2CrO4- → Ba(CrO4)2 + 2Na+ + 2 OH-

NaOH disappear with etOH washing.


I used of course electrode made from platin, cause other electrode occurs impurities wich hard to clean





[Edited on 5-9-2015 by Aqua-regia]