napoleon9
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make dry hex-1-yne
My teacher advice me that i make dry hex-1-yne by CaH2, but My Lab haven't it now. Please give me some advice.
thanks
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madscientist
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I assume you meant CaC<sub>2</sub>. What are the other reagents and conditions?
I weep at the sight of flaming acetic anhydride.
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napoleon9
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I'm sorry. I remember incorrect. Dry hex-1-yne by MS 4A. Please give me some advice.
thanks
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Paddywhacker
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mmmm.... MS 4A .... tricky.
MS 4A doesn't have any carbons in it, and dry hex-1-yne has at least six per molecule, so you are going to need something else..... most probably
something with carbons in it. Six carbons per molecule might be handy. Maybe glucose .... no ... too solid. I'm out of ideas.
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madscientist
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I think he means drying hex-1-yne with molecular sieves 4A.
I weep at the sight of flaming acetic anhydride.
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nitric
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Drying with CaCl2 and molecular sieves 4A should be dry enough for most reactions. If we had details of what you are going to do with the hex-1-yne,
we may be able to be a bit more detailed.
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napoleon9
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some my friend advice me that hexyne are dry by CaO or MgSO4 ????
If my Lab haven't MS 4A. How do you do dry hexyne ? why ? explain ? 
Please give me some advice
Thanks
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napoleon9
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hex-1-yne is Merck product, 98%. I don't find MS 4A in HO CHI MINH city, VIET NAM. how do you make drying hex-1-yne ? when you haven't MS 4A.
Please give me some advice .....
thank you 
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nitric
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You use other drying reagents, such as CaCl2, CO, Ca2C
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peach
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Drying agents
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not_important
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Note the using metal hydrides or reactive metals with 1-ynes may lead to replacement of the terminal hydrogen, forming H2(g). Strong bases can cause
isomerisation, especially if heated.
If the alkyne is really wet, perhaps start with Na2SO4, else go right to MgSO4. If there is likely to be alcohols in the product, use CaCl2 as the
preliminary drying agent. Follow by a polishing with CaSO4, low capacity thus the pretreatment with one of those other sulfates, but will make it
pretty dry. Although not quite as good as 3A or 4A sieves (it does better than silica gel), CaSO4 is cheap, easy to obtain, and easy to regenerate,
and is compatible with most organics (like Na2SO4 is as well).
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napoleon9
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i read book purification of lab
"1-Hexyne [693-02-7] M 82.2, b 12.5o/75mm, 7 1o/760mm
Distil it from NaBH4 to remove peroxides. Stand over sodium for 24hours, then fractionally distil it under reduced
pressure"
i bought hexyne of Merck 98%. If external cooling is provided by ice dry, Na wire was fire over bottle hexyne. After 24h, solution in bottle has red
yellow. it was colourless solution when it was into filter paper.
"correct or incorrect ????? "
If i made drying hexyne by silica gel ???? correct or incorrect ?????
can you show me some example ????
thanks
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