Calcium silicate

Calcium silicate
Names
	Preferred IUPAC name Calcium silicate
	Systematic IUPAC name Dicalcium silicate
	Other names Belite; Calcium monosilicate; Calcium hydrosilicate; Calcium metasilicate; Calcium orthosilicate; Micro-cell; Silene; Silicic acid calcium salt;
Identifiers
CAS Number	1344-95-2 ; 111811-33-7 hydrate ; 12168-85-3 calcium oxide ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:190294;
ChemSpider	14235 ; 23811 calcium oxide ;
ECHA InfoCard	100.014.282
EC Number	235-336-9;
E number	E552 (acidity regulators, ...)
KEGG	D03309 ;
MeSH	Calcium+silicate
PubChem CID	14941; 44154858 hydrate; 25523 calcium oxide;
UNII	S4255P4G5M ; 404G39282C calcium oxide ;
CompTox Dashboard (EPA)	DTXSID5049570 ;
	InChI InChI=1S/2Ca.O4Si/c;;1-5(2,3)4/q2*+2;-4 Key: JHLNERQLKQQLRZ-UHFFFAOYSA-N ;
	SMILES [Ca++].[Ca++].[O-][Si]([O-])([O-])[O-];
Properties
Chemical formula	Ca2O4Si
Molar mass	172.237 g·mol−1
Appearance	White crystals
Density	2.9 g/cm3 (solid)
Melting point	2,130 °C (3,870 °F; 2,400 K)
Solubility in water	0.01% (20 °C)
Thermochemistry
Std molar; entropy (S⦵298)	84 J/(mol·K)
Std enthalpy of; formation (ΔfH⦵298)	−1630 kJ/mol
Pharmacology
ATC code	A02AC02 (WHO)
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Irritant
NFPA 704 (fire diamond)	2 0 0
Flash point	Not applicable
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp)
REL (Recommended)	TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp)
IDLH (Immediate danger)	N.D.
Safety data sheet (SDS)
	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

Calcium silicate can refer to several silicates of calcium including:

CaO·SiO₂, wollastonite (CaSiO₃)
2CaO·SiO₂, larnite (Ca₂SiO₄)
3CaO·SiO₂, alite or (Ca₃SiO₅)
3CaO·2SiO₂, (Ca₃Si₂O₇).

This article focuses on Ca₂SiO₄, also known as calcium orthosilicate, or by the shortened trade name Cal-Sil/Calsil. All calcium silicates are white free-flowing powders. Being strong, cheap and nontoxic, they are components of important structural materials.

Names

Preferred IUPAC name Calcium silicate
Systematic IUPAC name Dicalcium silicate
Other names Belite Calcium monosilicate Calcium hydrosilicate Calcium metasilicate Calcium orthosilicate Micro-cell Silene Silicic acid calcium salt
Identifiers
CAS Number	1344-95-2^Y 111811-33-7 hydrate^Y 12168-85-3 calcium oxide^Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:190294
ChemSpider	14235^N 23811 calcium oxide^Y
ECHA InfoCard	100.014.282
EC Number	235-336-9
E number	E552 (acidity regulators, ...)
KEGG	D03309^N
MeSH	Calcium+silicate
PubChem CID	14941 44154858 hydrate 25523 calcium oxide
UNII	S4255P4G5M^Y 404G39282C calcium oxide^Y
CompTox Dashboard (EPA)	DTXSID5049570
InChI InChI=1S/2Ca.O4Si/c;;1-5(2,3)4/q2*+2;-4^N Key: JHLNERQLKQQLRZ-UHFFFAOYSA-N^N
SMILES [Ca++].[Ca++].[O-][Si]([O-])([O-])[O-]
Properties
Chemical formula	Ca₂O₄Si
Molar mass	172.237 g·mol⁻¹
Appearance	White crystals
Density	2.9 g/cm³ (solid)
Melting point	2,130 °C (3,870 °F; 2,400 K)
Solubility in water	0.01% (20 °C)
Thermochemistry
Std molar entropy (S^⦵₂₉₈)	84 J/(mol·K)
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	−1630 kJ/mol
Pharmacology
ATC code	A02AC02 (WHO)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
NFPA 704 (fire diamond)	2 0 0
Flash point	Not applicable
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 15 mg/m³ (total) TWA 5 mg/m³ (resp)
REL (Recommended)	TWA 10 mg/m³ (total) TWA 5 mg/m³ (resp)
IDLH (Immediate danger)	N.D.
Safety data sheet (SDS)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references