Lithium metasilicate

Lithium metasilicate
Names
IUPAC name Lithium metasilicate
Identifiers
CAS Number	10102-24-6^Y
3D model (JSmol)	Interactive image
ChemSpider	162106396
ECHA InfoCard	100.030.232
EC Number	233-270-5
PubChem CID	66243
UNII	5QDO50LGBD^Y
CompTox Dashboard (EPA)	DTXSID30904264
InChI InChI=1S/2Li.O3Si/c;;1-4(2)3/q2*+1;-2 Key: PAZHGORSDKKUPI-UHFFFAOYSA-N
SMILES [Li+].[Li+].[O-][Si](=O)[O-]
Properties
Chemical formula	Li₂SiO₃
Molar mass	89.566 g/mol
Appearance	colorless crystals
Density	2.52 g/cm³
Melting point	1,201 °C (2,194 °F; 1,474 K)
Solubility in water	insoluble
Refractive index (n_D)	1.584
Structure
Crystal structure	orthorhombic
Thermochemistry
Heat capacity (C)	99.1 J/mol K
Std molar entropy (S^⦵₂₉₈)	79.8 J/mol K
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	-1648 kJ/mol
Gibbs free energy (Δ_fG^⦵)	28 kJ/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

Lithium metasilicate is an ionic compound with the formula Li₂SiO₃

Preparation

Lithium metasilicate is prepared by the reaction of lithium carbonate and silicon dioxide at temperatures between 515 and 565 °C.^[1]

The melting of lithium metasilicate is used for the calibration of thermocouples.^[2]

^ Tang, Tao; Zhang, Zhi; Meng, Jian-Bo; Luo, De-Li (December 2009). "Synthesis and characterization of lithium silicate powders". Fusion Engineering and Design. 84 (12): 2124–2130. doi:10.1016/j.fusengdes.2009.02.017.
^ Biggar, Gordon M. (June 1972). "Diopside, lithium metasilicate, and the 1968 temperature scale". Mineralogical Magazine. 38 (298): 768–770. Bibcode:1972MinM...38..768B. doi:10.1180/minmag.1972.038.298.16. S2CID 129422457.