12AX7 - 12-6-2006 at 16:11
...Perperchloric acid..???
H-O-O-Cl(=O)3 that is to say.
Tim
=SkyNET= - 12-6-2006 at 20:23
Peroxychloric acid?
woelen - 15-6-2006 at 22:31
Does this really exist?? I think that mixing H2O2 and HClO4 just gives a mix, albeit a very powerfully oxidizing mix.
Pyrovus - 15-6-2006 at 22:53
Perchloric acid is a strong enough oxidising agent to oxidise hydrogen peroxide to oxygen:
H2O2 -> O2 + 2H+ +2e- [-0.68 V]
(1/2)Cl2 + 4H2O -> 8H+ + ClO4- +
7e- [-1.34 V]
Hence, the following reaction should occur:
2HClO4 + 7H2O2 -> Cl2 + 8H2O + 7O2
[Edited on 16-6-2006 by Pyrovus]
12AX7 - 16-6-2006 at 13:42
..But does it occur? Perchlorate is pretty stable when it's less than what, 70% is it?
Anyone got a drop of HClO4 and 30% H2O2 on hand? 
Real quickie impulsive test I
would think... suprised no one has yet?
Tim
The_Davster - 16-6-2006 at 15:18
Tried it....nothing happens other than a very slight rise in temperature. A squirt of 70% perchloric into a mL of35% peroxide.
If you go by redox potentials you also get that perchloric will react with water to give oxygen, which does not happen.
unionised - 17-6-2006 at 06:21
"nothing happens other than a very slight rise in temperature"
So something happened then otherwise there wouldn't have been a temperature change.
How would you know if there had been a reaction? If you got a peroxyperchlorate ion I guess it would show up with an IR spectrum but how else would
you test for it?
neutrino - 17-6-2006 at 07:06
It could have just been heat of solution. Sulfuric acid + water releases heat, so couldn't perchloric do the same?
12AX7 - 17-6-2006 at 08:06
Most obvious would be, can you make a peroxyperchlorate salt? Could one ever be stable? Adding KOH and cooling might be a possibility. (I don't
like the idea of K, since KClO4 is so insoluble; but almost everything else is monstrously soluble and hygroscopic -- is there anything reasonable
inbetween?)
From there, if found to be different, the salt could be redox titrated, simple enough since the peroxy part should be far less stable than the
perchlorate is. Or it could be reduced to chloride quantitatively somehow; heat to decomposition and measure the volume of oxygen perhaps.
Tim
unionised - 17-6-2006 at 09:20
"It could have just been heat of solution. Sulfuric acid + water releases heat, so couldn't perchloric do the same? "
True, but even that's a reaction of sorts.
Trying the experiment with water would be a useful check.