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Author Topic: How can I make colourless phosphoric acid?  (Read 3141 times)

faride

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How can I make colourless phosphoric acid?
« on: 02/11/2011 15:01:03 »
faride asked the Naked Scientists:
   
how can i make colorless phosphoric acid from green phosphoric acid 80%?

What do you think?
« Last Edit: 02/11/2011 15:01:03 by _system »


 

Offline lightarrow

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How can I make colourless phosphoric acid?
« Reply #1 on: 04/11/2011 15:25:20 »
How exactly did you get than green acid?
 

Offline Bored chemist

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How can I make colourless phosphoric acid?
« Reply #2 on: 04/11/2011 18:25:41 »
Crude phosphoric acid made by reacting  rock phosphate with sulphuric acid is greenish or brownish.
At least part of the colour is due to iron.
You can remove some of the impurities by ion exchange and solvent extraction.
However you won't get a very pure product. The usual way of getting high purity acid is to burn phosphorus to the pentoxide and react that with water.
That's expensive and energy intensive. If there was a better way, people would use it.
 

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How can I make colourless phosphoric acid?
« Reply #2 on: 04/11/2011 18:25:41 »

 

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