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Chemical elements
  Lithium
    Isotopes
    Energy
    Production
    Application
    Physical Properties
    Chemical Properties
      Lithium hydride
      Lithium chloride
      Lithium bromide
      Lithium iodide
      Lithium iodide tetrachloride
      Lithium hypochlorite
      Lithium chlorate
      Lithium perchlorate
      Lithium bromate
      Lithium iodate
      Lithium periodates
      Lithium monoxide
      Lithium peroxide
      Lithium hydroxide
      Lithium monosulphide
      Lithium polysulphides
      Lithium sulphite
      Lithium sulphate
      Lithium persulphate
      Lithium thiosulphate
      Lithium dithionate
      Lithium selenide
      Lithium selenite
      Lithium selenate
      Lithium chromate
      Lithium permanganate
      Lithium molybdates
      Lithium nitride
      Lithium hydrazoate
      Lithamide
      Lithium nitrite
      Lithium nitrate
      Lithium phosphide
      Lithium orthophosphate
      Lithium pyrophosphate
      Lithium metaphosphate
      Lithium arsenide
      Lithium meta-arsenite
      Lithium arsenate
      Lithium antimonide
      Lithium antimonate
      Lithium carbide
      Lithium carbonate
      Lithium percarbonate
      Lithium cyanide
      Lithium thiocyanate
      Lithium silicide
      Lithium silicates
      Lithium borates

Lithium borates

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A borate of the formula LiBO₂,8H₂O crystallizes from mixed solutions of lithium hydroxide and boric acid. At 47° C. it melts in its water of crystallization, loses seven molecules of water at 110° C., and the eighth at 160° C. The tenacity with which the final molecule of water is retained points to the possibility of the salt being an orthoborate, LiH₂BO₃,7H₂O. At 14.7° C. its density is 1.397.

The anhydrous metaborate, LiBO₂, is precipitated by the interaction of alcoholic solutions of a lithium salt and boric acid, and can also be obtained by fusing lithium carbonate with boric acid. It forms triclinic leaflets of pearl-like lustre, and melts at 843° C. Boiling with water converts it into the octahydrate.

Le Chatelier's data for the solubility of the anhydrous metaborate in water are given in the following table -

Solubility of Lithium Metaborate.

Temperature, °C	0	10	20	30	40	45
Grams LiBO₂ in 100 grams of water	0.7	1.4	2.6	4.9	11	20

For the heat of hydration Le Chatelier found

[LiBO₂]+8H₂O=[LiBO₂,8H₂O]+21.7 Cal.,

and for the heat absorbed by solution of the hydrate

[LiBO₂,8H₂O]+Aq. =LiBO₂,Aq. -14.2 Cal.

A polyborate, Li₂B₈O₁₃, is obtained in crystalline form by heating lithium carbonate with excess of boric acid at 500° to 600° C. for a long time.