gnitseretni
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Need Hydrazine hydrate
I'm looking for hydrazine hydrate, but I can't find a company that will sell it to individuals. (Well, sciencelab is not an option  ) Making my own isn't really an option either. I don't suppose there's anyone here who
could sell me some? I don't need much, 100ml should last me a while.. but I'll take 25ml if that's all you can spare.
I hope this is OK with the mods. If not, feel free to delete it.
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woelen
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This question is OK for me. I, however, see quite a lot of practical problems. Shipping this chemical must be very expensive. Do not allow shipping of
this nasty thing by normal mail. A small leak of the container can have really bad (legal) effects.
Why not try to obtain a hydrazine salt, such as hydrazinium sulfate (N2H4.H2SO4) or hydrazinium chloride (N2H4.2HCl)? These are solids, which can be
handled easily. Neutralizing a solution of these with NaOH, such that your solution is neutral gives you a solution of hydrazine hydrate, with Na2SO4
(or NaCl) in solution.
When your solution is neutral, then you can distill in glass (do not use excess NaOH, this wil lead to damage to your glassware). Simply boil off the
liquid until some wet paste remains and collect the vapors. In this way a dilute hydrazine hydrate solution comes over at somewhere around 110 C).
This dilute hydrazine solution does not destroy your glassware and can be safely handled. Only dilute solutions can be obtained in this way (10%
hydrazine or so is achievable). Making the solution more concentrated requires non-glass equipment, because concentrated hydrazine hydrate is quite
alkaline and slowly attacks glass when it is hot.
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Rogeryermaw
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Quote: Originally posted by woelen  | This question is OK for me. I, however, see quite a lot of practical problems. Shipping this chemical must be very expensive. Do not allow shipping of
this nasty thing by normal mail. A small leak of the container can have really bad (legal) effects.
Why not try to obtain a hydrazine salt, such as hydrazinium sulfate (N2H4.H2SO4) or hydrazinium chloride (N2H4.2HCl)? These are solids, which can be
handled easily. Neutralizing a solution of these with NaOH, such that your solution is neutral gives you a solution of hydrazine hydrate, with Na2SO4
(or NaCl) in solution.
When your solution is neutral, then you can distill in glass (do not use excess NaOH, this wil lead to damage to your glassware). Simply boil off the
liquid until some wet paste remains and collect the vapors. In this way a dilute hydrazine hydrate solution comes over at somewhere around 110 C).
This dilute hydrazine solution does not destroy your glassware and can be safely handled. Only dilute solutions can be obtained in this way (10%
hydrazine or so is achievable). Making the solution more concentrated requires non-glass equipment, because concentrated hydrazine hydrate is quite
alkaline and slowly attacks glass when it is hot. |
would using a stainless vessel and anhydrous base yield anhydrous hydrazine?
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woelen
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No, you would not get anhydrous hydrazine. If e.g. waterfree NaOH were used with dry N2H4.2HCl, then you would get hydrazine hydrate and NaCl.
You could mix stoichiometric amounts of NaOH and a hydrazinium salts and crunch the mix, so that it is finely divided. Then add a drop of water to get
the reaction going. It will be fairly exothermic.
If you do this, then you definitely need a non-glass vessel if you want to distill off the hydrazine hydrate. Besides that, it is quite dangerous.
Distilling concentrated hydrazine hydrate may lead to explosion.
So, I would stick to more dilute things. E.g. take nearly stoichiometric amounts of a hydrazinium salt and NaOH, using a slight excess of the
hydrazinium salt (just a few percents excess is OK) to assure that the mix does not become strongly alkaline. Prepare a concentrated solution of the
NaOH in water and then add the hydrazinium salt and dissolve all of it in a hot solution. If not all dissolves in the hot solution, then add a little
more water. When you have a clear hot solution, then distill off the liquid until a white mud remains. You should not use a fractionating column, just
boil off all liquid. The boiling points of water and hydrazine hydrate are close enough so that hardly any separation occurs and the large amount of
salt in the solution makes the separation even less (which is good in this situation).
This process works better with the chloride than with the sulfate. The chloride dissolves easily and the resulting sodium salt also remains in
solution more easily and allows boiling off more liquid without a lot of bumping and splattering.
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Rogeryermaw
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i know that even with a nitrogen atmosphere, anhydrous hydrazine is INCREDIBLY dangerous so my query is only hypothetical. don't worry, i have no
intention of attempting it. i was just curious what steps were involved in releasing pure hydrazine from the sulfate. this however is a question i
could probably answer with a good read.
thank you, woelen, for your clear answer. very helpful.
[Edited on 13-9-2012 by Rogeryermaw]
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