TLutman
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Curious about HS result
Watched chemplayer, dougs lab, Nile red and NurdRage videos on hydrazine sulfate and wanted to give it a go.
I adjusted quantities down to what I had in H₂SO₄, (need to distill more).
125ml NaClO 10% pool cleaner .181moles
16g NaOH drain cleaner
.375g Knox gelatine
11.42g urea recryst from DEF
50ml 50% H₂SO₄
Followed the videos and all went very similar, except for the foam volcano of Nile red.
I expected only 5ish grams. I got 17. Thought maybe I cooled too much before filtering and have loads of sodium sulfate, so I tried using
guesstimates with the solubility of both and used 50ml of water with the batch, heated w/stirring, and allowed to cool. Not all dissolved, nor did I
expect it to, particularly all the HS.
I decanted into a clean beaker and vac filtered the powder. Rough weight showed a bit better than 14g. Didn’t expect that. That 3g is about how
much HS I figured would be lost.
Either I am not seeing what the 50% yield is based on or I have something else. It isn’t very soluble.
After some searching all over the place fora way to confirm HS, I tried using an acidified KMnO₄ soln and a small amount of crystals turned it to
rust red, yellow, then clear. Another test I saw was supposed to be a violent reaction when placed in an acidified conc sol of chlorate. Nothing
happened
Any other means of testing for HS?
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woelen
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Mood: interested
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A good test for hydrazine sulfate is dissolving some NaOH in water and then dissolving the HS. If you drop a little solution of copper sulfate into
the alkaline solution, you should get an orange or brown precipitate of copper(I) oxide, or even some (impure) elemental copper metal. If no HS is
present, then you get the familiar bright blue precipitate of copper(II) hydroxide. If only traces of HS are present, you get a dirty blue/green
precipitate. If your product contains a decent amount of HS, then you certainly should not get any blue in your precipitate when you add a few drops
of the copper sulfate solution.
HS only is very sparingly soluble in cold water, but it dissolves more easily in dilute NaOH. Sodium sulfate on the other hand dissolves more
difficultly in dilute NaOH.
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TLutman
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Performed your test this morning. The Compound readily dissolved in a weak NaOH solution with no residuals. A drop of copper II sulfate solution
initially just turned to the hydroxide, but slowly turned brown over 10 sec with no stirring. Another drop was added and it turned brown immediately
with a little shaking of the tube.
There are 2 distinct components that formed. One fluffy and collecting at the top, and another more powdery collecting at the bottom.
Seems like there is HS in there, but do the numbers add up? I initially had about .130M of HS. I keep reading yields of 50 ish percent in general,
with some getting up to mid 60% yield, but I’m not sure what that is based on.
Edit: after sitting for a short while, all solids are in the bottom of the tube in the form of a fine powder
[Edited on 31-5-2021 by TLutman]
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