LD5050
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Phosphoric acid in H2O2? and concentrating by evaporation
I bought a 946ml bottle of Hydrogen peroxide from a hair salon shop. The bottle says 40 volume clear stabilized formula. The bottle doesn't say the
Hydrogen peroxide percentage but a similar bottle of 40 volume stated the percentage and it was 12% I'm assuming this is the same percentage. The
bottles ingredients are Water, Hydrogen Peroxide, and Phosphoric Acid.
I looked up the MSDS but it doesn't give the percentage of phosphoric acid.
My questions are:
Is there a way to remove the phosphoric acid?
Is there even enough acid to effect a procedure that requires hydrogen peroxide?
What concentration is obtainable from slowly evaporating off the water? Does H2O2 form any azeotropes with water? I'm going to do a google search on
this right now but I figured I would ask here as well.
Theoretically I could get 90%+ if I boil off enough water?
[Edited on 3-25-2017 by LD5050]
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Melgar
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The phosphoric acid is an acidic buffer, and H2O2 tends to be stabilized by oxoacids. Aluminum might work to react with it, since peroxide wouldn't react with its already-oxidized surface and phosphoric acid would
gradually form aluminum phosphate on the surface, which is insoluble in virtually everything. However, this would only happen slowly, and the
aluminum would have to be smooth enough to not have nucleation sites that would result in decomposition of the peroxide.
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LD5050
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So I evaporated the 12% H2O2 from 946ml down to 110ml. Assuming this doesn't form an azeotrope with water would it be safe to assume I have 90%+ H2O2?
I put a few drops onto about 100mg of Manganese Dioxide and it resulted in a powerful violent reaction so I know the concentration is pretty high. I
also got some on my fingers which burned a bit and seem to now be bleached white.
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Metacelsus
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It's probably not 90% because some would have (inevitably) decomposed, and some would have evaporated.
Can you measure the density?
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LD5050
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So I did a test to determine the approx. concentration by filling a 100ml graduated cylinder ful of water and placing it upside down in a beaker of
water. I pull a small house into the Grad. cylinder and attached the other end of the hose to a rubber stopper and fitted into a test tube loaded with
.5ml of H2O2 and a few mg of mangenese dioxide. When I mixed the two inside of the test tube it gave off O2 and the water level in the grad cylinder
went to about 10 ml above the 100ml mark.
So .5ml H2O2 gave off around 110ml of O2. If 40 volume (12%) H2O2 gives off 40 ml of O2 per 1ml of H2O2 and my 1ml H2O2 gave off 220ml O2 (.5ml=110ml
multiply by 2 =220) That means I have around 66% Hydrogen Peroxide (220/40=5.5 multiply by 12=66%)
Not bad... I cant imagine what 90% is like, just a half a drop of the 66% on my hand burns like hell and turns it white! not to mention the reaction I
get when mixed with mangenese dioxide...
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XeonTheMGPony
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Back in the rocket days when we where just learning 90% was common part of the propellant mix, one of the scientists said that if your hand where to
go into the beaker only bones would come out of it.
I do not know the truth of that on living flesh but I can say that 90% will ignite most things when simply dripped on it!
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zed
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Hydrometer.
H2O2 concentration may be determined thereby. Tables of data exist.
[Edited on 28-3-2017 by zed]
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