Sodium metasilicate

Sodium metasilicate
Names
	IUPAC name Sodium metasilicate
Identifiers
CAS Number	6834-92-0 ; pentahydrate: 10213-79-3; nonahydrate: 13517-24-3 ;
3D model (JSmol)	Interactive image;
Abbreviations	E550
ChEBI	CHEBI:60720 ;
ChemSpider	21758 ;
ECHA InfoCard	100.027.193
EC Number	600-279-4229-912-9;
MeSH	Sodium+metasilicate
PubChem CID	23266; pentahydrate: 61495; nonahydrate: 61639;
RTECS number	VV9275000;
UNII	052612U92L ; nonahydrate: D8D44215LZ ;
UN number	1759 3253
CompTox Dashboard (EPA)	DTXSID7029669 ;
	InChI InChI=1S/2Na.O3Si/c;;1-4(2)3/q2+1;-2 Key: NTHWMYGWWRZVTN-UHFFFAOYSA-N ; InChI=1/2Na.O3Si/c;;1-4(2)3/q2+1;-2 Key: NTHWMYGWWRZVTN-UHFFFAOYAB;
	SMILES [Na+].[Na+].[O-][Si]([O-])=O;
Properties
Chemical formula	Na2SiO3
Molar mass	122.062 g·mol−1
Appearance	White crystals
Density	2.61 g/cm3
Melting point	1,088 °C (1,990 °F; 1,361 K)
Solubility in water	22.2 g/100 ml (25 °C) ; 160.6 g/100 ml (80 °C)
Solubility	insoluble in alcohol
Refractive index (nD)	1.52
Thermochemistry
Heat capacity (C)	111.8 J/(K·mol)
Std molar; entropy (S⦵298)	113.71 J/(K·mol)
Std enthalpy of; formation (ΔfH⦵298)	−1561.43 kJ/mol
Gibbs free energy (ΔfG⦵)	−1427 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H314, H315, H319, H335
Precautionary statements	P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P330, P332+P313, P337+P313, P362, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 0 0
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	1153 (rat, oral)
Safety data sheet (SDS)	Avantor Performance Materials
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Sodium metasilicate is the chemical substance with formula Na
₂SiO
₃, which is the main component of commercial sodium silicate solutions. It is an ionic compound consisting of sodium cations Na⁺
and the polymeric metasilicate anions [–SiO²⁻
₃–]_n. It is a colorless crystalline hygroscopic and deliquescent solid, soluble in water (giving an alkaline solution) but not in alcohols.