Sciencemadness Discussion Board - Test reaction for hydrazine

Test reaction for hydrazine

dangerous amateur - 6-7-2013 at 13:31

Hi,

do you guys know a simple test reaction for hydrazine solutions?

I've got a batch of hydrazine sulfate here, how can i check it's quality, or at least proof it is what the seller claims it to be?

unionised - 7-7-2013 at 04:23

Production of benzalazine by reaction with benzaldehyde?

weiming1998 - 7-7-2013 at 04:40

Quote: Originally posted by dangerous amateur

Hi,

do you guys know a simple test reaction for hydrazine solutions?

I've got a batch of hydrazine sulfate here, how can i check it's quality, or at least proof it is what the seller claims it to be?

Hydrazine is known as a reducing agent, so it will be able to reduce mild oxidizing agents such as iodine, indicating its presence. Just combine excess hydrazine sulfate with dilute NaOH solution and add iodine. The iodine will dissolve away leaving a colourless solution and the hydrazine will be oxidized to nitrogen, which could be seen as bubbles.

unionised - 7-7-2013 at 06:57

Quote: Originally posted by weiming1998

Quote: Originally posted by dangerous amateur

Whereas, without the hydrazine, you will see the solution decolourised by the reaction of iodine with sodium hydroxide.

bfesser - 7-7-2013 at 07:35

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[Edited on 7/9/13 by bfesser]

Bot0nist - 7-7-2013 at 10:02

Carefully add a drop to some small chunks and powder TCCA. Be very carefull though. TCCA is very violent with ammonia solutions, and probably much more so with hydrazine solutions.

This is probably not the best way to test its reducing properties though. Be safe, good luck.

woelen - 7-7-2013 at 11:18

Dissolve some of the material in water and add iodine. Not even NaOH is needed. The iodine dissolves, fizzling away and a colorless solution is obtained. If there is no hydrazine in the salt, then the iodine will not dissolve.

unionised - 7-7-2013 at 11:57

Unless, of course someone has sold him ammonia labelled as hydrazine.

dangerous amateur - 7-7-2013 at 12:15

Unfortunately I don't have both TCCA and iodine here.

I was told the material might also be hydroxylamine sulfate.
Unfortunately something that reacts similar in many reactions compared to hydrazine...

Fantasma4500 - 7-7-2013 at 13:23

wouldnt hydrazine sulfate react with lead nitrate to form lead sulfate, and by that you could possibly find the molarity of the solution?
dont know if its possible to work this way with organics, if you can call hydrazine ions that

density might work also

bfesser - 7-7-2013 at 13:31

Let me preface my post with a disclaimer:
I've been doing a little studying and searching on <a href="http://en.wikipedia.org/wiki/Hydrazine" target="_blank">hydrazine</a> <img src="../scipics/_wiki.png" /> and <a href="http://en.wikipedia.org/wiki/Hydrazine_sulfate" target="_blank">hydrazine sulfate</a> <img src="../scipics/_wiki.png" />, but I am by no means an expert. These compounds are quite hazardous. Neither ScienceMadness.org nor myself will be held responsible in the event that you harm yourself or others by following my amateur advice! Use your own informed judgement, and carefully study the toxicology and hazards associated with these compounds before proceeding.

<hr width="800" />
Have you considered attempting to verify the identity of your solution by testing its physical properties? I assume that your supplier specified a concentration for the aqueous hydrazine sulfate. I don't know what equipment you have; perhaps you could test the <a href="http://en.wikipedia.org/wiki/Specific_gravity" target="_blank">specific gravity</a> <img src="../scipics/_wiki.png" /> of the solution by weighing a carefully measured volume at a given temperature, or with an appropriate <a href="http://en.wikipedia.org/wiki/Hydrometer" target="_blank">hydrometer</a> <img src="../scipics/_wiki.png" />. (I don't suppose you have a <a href="http://en.wikipedia.org/wiki/Pycnometer#Pycnometer" target="_blank">pycnometer</a> <img src="../scipics/_wiki.png" /> on hand?) You could then compare the values to what you would expect for the solution. This may not provide conclusive proof, but it's something.

As far as chemical tests are concerned, I've managed to find a few resources that might be of use:
<ul><li><a href="viewthread.php?tid=1128#pid10456">test: copper dihydrazinium sulfate</a></li><li>The micro-determination of hydrazine salts and certain derivatives
M. Z. Barakat, Monier Shaker
Analyst, 1963,88, 59-63
DOI: <a href="http://dx.doi.org/10.1039/AN9638800059" target="_blank">10.1039/AN9638800059</a> <img src="../scipics/_ext.png" /></li><li><a href="http://books.google.com/books/about/The_chemistry_of_hydrazine.html?id=VTZRAAAAMAAJ" target="_blank">The Chemistry of Hydrazine</a> <img src="../scipics/_ext.png" />
Ludwig Frederick Audrieth, Betty Ackerson Ogg
Wiley, 1951.</li></ul>

[edit] Apparently Antiswat posted these same ideas while I was still typing...

[Edited on 7/9/13 by bfesser]

adamsium - 7-7-2013 at 19:32

dangerous amateur - is your material already in solution, or are you just asking how you could test it if you were to make a solution from it?

If you have dry material and the main question is really just whether it is hydrazine sulfate or hydroxylammonium sulfate, you could exploit their differences in melting point and solubility. Hydroxylammonium sulfate is very soluble in water, while hydrazine sulfate is only slightly soluble in water. The melting point of hydrazine sulfate is around 254 C (though a couple of sources do say it decomposes at this temperature), while hydroxylammonium sulfate decomposes ~150 C (various sources report values between around 120 C and 170 C).

The easiest property to test here would obviously be solubility differences, as they are sufficiently different (by a factor of about 20 times) that it would be very easy to distinguish between the two compounds on this basis if the only real question is which of the two your material is.

Sources:
SI Chemical Data, 6th Ed
SciFinder
and the always trusty wikipedia http://en.wikipedia.org/wiki/Hydroxylammonium_sulfate , http://en.wikipedia.org/wiki/Hydrazine_sulfate

dangerous amateur - 8-7-2013 at 02:16

Thank you for your answers.

Yes I know toxicity, i only mess around with very small amounts and only do it outside.

Quote:

the always trusty wikipedia

I'm sorry, I allready did that. And i found the differences in solubility not very great. Only I oversaw that the figure for Hydroxylamine sulfate was per 100ml and not per liter.

I'll try to determine solubility tomorrow.

woelen - 8-7-2013 at 10:18

Oh yes, if the only doubt is whether it is hydroxyl ammonium sulfate or hydrazinium sulfate, then the test is easy. If you put some hydroxyl ammonium sulfate in water, then it quickly dissolves, while hydrazinium sulfate requires a lot of shaking and only a small quantity dissolves (somewhere in between KClO3 and KClO4).