Preparation of Perchloric Acid
Mon. Scient., XI 961
In:— The Journal of the Society of Chemical Industry
1 [4] 149. 29 April 1882
It is recommended that this acid should be prepared by the user
himself, the cost in this case being 20 to 25 francs per kilo.,
whereas the manufactures demand 90 francs per kilo. It can be
prepared in the following manner without the slightest danger.
[Forsooth!] Pure barium chlorate is dissolved in luke-warm water
and dilute sulphuric acid is added. The precipitate is allowed to
settle, and the clear liquid poured off, and the barium sulphate
thoroughly washed. The chloric acid solution becomes yellow, and upon further evaporation produces a peculiar noise. The
liquid is divided into two parts, placed in two dishes, 19
centimeters in diameter and containing about 700 cubic
centimeters, and evaporated further until the liquid is quite
decolourised and thick white fumes are given off. In order to
lessen this unavoidable loss of perchloric acid the liquid can be
diluted from time to time with a little water. The colourless liquid
is then distilled in a retort heated on a sand bath and collected in
a long-necked receiver. The perchloric acid so obtained contains
traces of iron. From 4 kilos of barium chlorate, 1 kilo. of perchloric
acid of 45o B. is obtained. The barium chlorate occurs in
commerce, and costs 4 francs the kilo.—M.J.L.
densest - 25-4-2010 at 14:05
Heh. Pure barium chlorate, huh? The last time I heard, the only supplier left in the US who would sell to individuals required pickup at his location
because shipping it was fraught with regulations and a few real hazards.
Even BaCl2 is hard to come by, though BaSO4 is easy and can be calcined to BaO if one is sufficiently extreme. BaClO3 from pharmaceutical sulfate
should not be contaminated with iron, which difference might make the reactions not produce the mentioned sound. I believe that Fe+3 and Fe2O3 can be
potent catalysts, though their interaction with ClO3 and friends I am utterly ignorant. Perhaps ceramic grade sulfate would be more correct to produce
the 1882 item.
Heh. Pure barium chlorate, huh? The last time I heard, the only supplier left in the US who would sell to individuals required pickup at his location
because shipping it was fraught with regulations and a few real hazards.
This dobe the reason I have not attempted the experiment.
However, in the usual place you can occasionally find people
selling BaClO3 who do not know/care about hazmat shipping.
Attachment: LABBLAST.tif (145kB) This file has been downloaded 650 timesnot_important - 25-4-2010 at 21:45
Ceramics grade BaCO3. Sometimes this contains the sulfide, so do the next steps with good ventilation.
If all you have is tech HCl, dilute it to roughly 18-20 percent, and distill off the constant boiling hydrochloric acid. Use an antispray bulb, short
column, or glass wool 'plug' to prevent spray droplets from carrying over iron into the distillate.
Dissolve BaCO3 in hydrochloric acid. Add a bit of HNO3, H2O2, or bubble Cl2 through the solution; in all cases to convert Fe(II) to Fe(III). Heat the
solution, slowly add a paste of BaCO3 and DI water with good stirring until there is an obvious excess of the carbonate. Boil the solution for some
minutes, Fe and Mn will precipitate out on the excess carbonate as hydroxides, hydrated oxides, or basic carbonates - darkening the white BaCO3 if
there is more than a trace of Fe or Mn. Filter off the excess carbonate, test the filtrate for Fe and if tests positive repeat the
oxidation/BaCO3/filter addition steps; otherwise crystallise BaCl2 out of the filtrate.
Formatik - 29-4-2010 at 10:56
Try calcium chlorate and oxalic acid. Caclium oxalate is around as insoluble as BaSO4.Pomzazed - 29-4-2010 at 11:02
"produces a peculiar noise"
still wonder what this is xDa_bab - 29-4-2010 at 11:09
Nitrogen triiodide crystals caught on the wall of the beaker crack and pop when you swirl the suspension of them. This is caused by the liquid that
crashes the crystals against the wall. Probably something similar? I'd try it.
