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WGTR
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It's going to be hard to ensure that your hydrogen gas is dry in that case. Traces of moisture may speed the formation of lithium hydride the way
that it does for nitride and oxides, but I think it's more likely that the lithium will react with the moisture faster than it does with the hydrogen,
leaving you a mass of lithium hydroxide. But I don't know if this would be the case. That would be a project for you.
One useful resource is Leonid Lerner's book "Small-Scale Synthesis of Laboratory Reagents with Reaction Modeling", where he discusses the formation of
lithium hydride (pg 73-79). I believe he goes by the name Len1 here on SM, if I remember correctly. It's a good book for explaining hands-on
methods for preparing alkali metals, etc. The relevant parts may be available to you on Google books, if you search for it.
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bismuthate
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ok I can get rid of all moisture by using silica coating the walls ot the litium container with silica gel or CaCl. also water won't evaporate easily
at high pressure.
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AJKOER
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OK, here is an extract of Atomistry.com (see http://lithium.atomistry.com/lithium_carbide.html ) on the preparation and some properties of C2Li2:
"The Lithium carbide, Li2C2 was first prepared by Moissan by the reduction of lithium carbonate with charcoal in the electric furnace -
Li2CO3+4C=Li2C2+3CO.
Tucker and Moody were unable to prepare the almost pure carbide described by Moissan, and attributed their failure to the very small
temperature-interval between the formation and the decomposition of the substance. The carbide is also formed by the interaction of lithium and any of
the allotropic modifications of carbon in vacuum at dull red heat; and by the combination of the metal with carbon monoxide or dioxide, or with
ethylene or acetylene, an impure product is obtained.
Lithium carbide is a white or grey crystalline substance, its density at 18° C. being 1.65. At bright red heat it is decomposed, and Tucker and Moody
found that at 925° C. and a pressure of fifty pounds to the square inch it absorbs nitrogen freely with formation of cyanamide, dicyanamide, and
cyanide. It is a powerful reducer, decomposing water energetically at ordinary temperatures with formation of acetylene"
Also, on Lithium carbonate, to quote Atomistry.com (see http://lithium.atomistry.com/lithium_carbonate.html ):
"When heated below 1000° C. lithium carbonate undergoes partial decomposition into the oxide and carbon dioxide, a resemblance to calcium, but a
distinction from sodium and potassium -
Li2CO3=Li2O+CO2"
And as:
Li2O + C --> 2 Li + CO or 2 Li2O + C --> 4 Li + CO2
it appears that C2Li2 may be formed as stated above "by the combination of the metal with carbon monoxide or dioxide". However, the source's comment
to quote "an impure product is obtained" may also apply to the CO/CO2 path. If so, the reaction pathway may be more complex.
[EDIT] Interestingly, here is the reversible net reaction cited (see http://calcium.atomistry.com/calcium_carbide.html ) for the formation of Calcium carbide, CaC2:
CaO + 3C ⇔ CaC2 + CO
As such, I would not be surprised if the action of CO on Li, absence any O2, formed a mixed sample containing Li2O.
[Edited on 5-10-2013 by AJKOER]
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bismuthate
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Sounds great, but i can't use it because i wanted low heat.
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