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iodine and bromine


nitric
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"no, doing the above will make the halide Acid, not the Element itself"

Want to bet?

You may not get a brilliant yield, but it certainly works.

If you want HI or HBr you are better off using phosphoric acid- sulphuric oxidised the halide to the free halogen

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no, doing the above will make the halide Acid, not the Element itself"

Want to bet?

You may not get a brilliant yield, but it certainly works.

If you want HI or HBr you are better off using phosphoric acid- sulphuric oxidised the halide to the free halogen

 

I'd say Halide acid is formed but since the reducing ability increases from flourine to iodine, Iodide ions in the halide acid are oxidised and reduces sulphuric acid to sulphur and sulphur dioxide.

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There is some use for both. By using sulfuric acid to liberate bromine from KBR would be the quickest, cheapest and least dangerous method. The oxidation stops when bromine is produced. If you are intersested, this is a two part reaction:

 

1.) KBr + H2SO4 -------> KHSO4 + HBr (sulfuric acid acts as an acid)

2.) 2HBr + H2SO4 ------> Br2 + SO2 + 2H2O (sulfuric acid acts as an oxidising agent)

Excess acid must be used

 

Hydrogen iodide proceed to further react with sulfuric acid, so Iodine is completely obtained from reacting with sulfuric acid, but other reactions take place that produce substances that take more time to safely remove (yet all Iodine will be liberated).

 

1.)KI + H2SO4 ---------> KHSO4 + HI

2.)2HI + H2SO4 -------> I2 + SO2 + 2H2O

3.)6HI + H2SO4 -------> 3I2 + S + 4H2O

4.)8HI + H2SO4 -------> 4I2 + H2S + 4H2O

 

To obtain Iodine, a simple redox reaction can be performed. Simply add the KI with chlorine.

2KI + Cl2 --------> 2KCl + I2

 

Best of luck.

However, these are extremely harmful and potentially problematic chemicals.

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I understand that, I realize that F2 would be stupid to use in actual practice, but in theory it would work. in that sense, it is not wrong, definitely stupid and unnecessary when you have access to the more safe but still incredibly toxic chlorine, but it would work

 

its not like some amateur lab would be able to whip out a liter with no problem....

 

I seriously doubt nitric (the thread originator) would have access to something like fluorine if he was asking a question like this

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Alright guys, sorry I wasn't clear enough.

 

Here is what I ment.

 

Flourine gas has the potential to replace chlorine and bromine and iodine because it is a stonger oxidizing agent.

 

In this sense, It would replace the I and Br from KI and KBr. You would obviously have the side reactions then occur.

 

I did not mean for this to be the actual method by any means.

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come on guys

 

I get it. It wouldn't have worked. I was wrong and you guys were right.

 

I did spell it right in the previous posts, I was typing too fast.

 

None the less, I will agree with you that Fluorine gas would not work in this instance or many others. All that I meant was that it would have the potential to kick I2 and Br2 out of the KI and KBr.

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it`s cleaner if you use the a Bromate or Iodate as the oxidiser though, the Bromine synth becomes really nice then as you can premix these 2 powders and store them away without incompatibility issues, and just add acid when ever you want the bromine.

It saves a lot trouble with storage issues too.

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  • 4 months later...

because bromine is very easy to make gas at 20ºC and they are very toxic

you must use any nitrite for start the reaction.

 

I've use pure HNO3 with bromides and nothing happend

but if you put some nitrite on it

wov

may be is the NO2 intermedie

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I use a KBr (sometimes LiBr) and 10% nitric acid soln quite regularly and when I make the reagent up there really isn`t anything apparent happening, but if left to stand for a while (a few weeks to months in my case) there is a slight Br2 smell and discoloration.

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