Jor
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Registered: 21-11-2007
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periodic acid solution, evaporate without reduced pressure?
I'm currently doing a synthesis on periodates.
My first step is complete, oxidation of iodine with sodium chlorate solution, with nitric acid catalyst.
I want to make some NaIO4, and some H5IO6.
In Brauer, periodic acid is prepared by adding bariumperiodate to concentrated nitric acid, because Ba(NO3)2 is insoluble in conc. HNO3. After
filtration the solution is evaporated at reduced pressure at 70C.
Is this really necessary? Is it, because periodic acid decomposes to possibly iodic acid when heated to 100C?
If it can only be done at reduced pressure, are there alternatives to get the periodic acid out of solution, e.g by adding acetone?
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Per
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The first thing I can´t understand at this prescription is that the conc. HNO3 should be also distilled at reduced pressure and 70°C...
My second thought is, is HIO4 also able to explode as anhydrous HClO4 is, may the vacuum is employed because of this reason.
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DJF90
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Its the conc. nitric that is distilled at 70C under reduced pressure, and this should leave behind your periodic acid as it only melts at 122C... I
assume that it decomposes when it melts and conc. nitric (68%) boils at about 120C at standard pressure, so the vacuum is employed to remove the
nitric without decomposing the periodic acid?
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