Calcium carbide

Calcium carbide
Names
	Preferred IUPAC name Calcium acetylide
	Systematic IUPAC name Calcium ethynediide
	Other names Calcium percarbide; Calcium carbide; Calcium dicarbide;
Identifiers
CAS Number	75-20-7 ;
3D model (JSmol)	Interactive image;
ChemSpider	6112 ;
ECHA InfoCard	100.000.772
EC Number	200-848-3;
PubChem CID	6352;
UNII	846WNV4A5F ;
CompTox Dashboard (EPA)	DTXSID4026399 ;
	InChI InChI=1S/C2.Ca/c1-2;/q-2;+2 Key: UIXRSLJINYRGFQ-UHFFFAOYSA-N ; InChI=1/C2.Ca/c1-2;/q-2;+2 Key: UIXRSLJINYRGFQ-UHFFFAOYAI;
	SMILES [Ca+2].[C-]#[C-];
Properties
Chemical formula	CaC2
Molar mass	64.100 g·mol−1
Appearance	White powder or colorless crystals, grey/brown/black crystals if impure
Density	2.22 g/cm3
Melting point	2,160 °C (3,920 °F; 2,430 K)
Boiling point	2,300 °C (4,170 °F; 2,570 K)
Solubility in water	Reacts to produce Acetylene
Structure
Crystal structure	Tetragonal (I phase) ; Monoclinic (II phase) ; Monoclinic (III phase)
Space group	I4/mmm (I phase) ; C2/c (II phase) ; C2/m (III phase)
Coordination geometry	6
Thermochemistry
Std molar; entropy (S⦵298)	70 J/(mol·K)
Std enthalpy of; formation (ΔfH⦵298)	−63 kJ/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Reacts with water to release acetylene gas
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H260
NFPA 704 (fire diamond)	1 4 2 W
Autoignition; temperature	305 °C (581 °F; 578 K) (acetylene)
Related compounds
Related compounds	Strontium carbide; Barium carbide;
	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 carbide, also known as calcium acetylide, is a chemical compound with the chemical formula of Ca C₂. Its main use industrially is in the production of acetylene and calcium cyanamide.

The pure material is colorless, while pieces of technical-grade calcium carbide are grey or brown and consist of about 80–85% of CaC₂ (the rest is CaO (calcium oxide), Ca₃P₂ (calcium phosphide), CaS (calcium sulfide), Ca₃N₂ (calcium nitride), SiC (silicon carbide), C (carbon), etc.). In the presence of trace moisture, technical-grade calcium carbide emits an unpleasant odor reminiscent of garlic.

Applications of calcium carbide include manufacture of acetylene gas, generation of acetylene in carbide lamps, manufacture of chemicals for fertilizer, and steelmaking.

Names


Preferred IUPAC name Calcium acetylide
Systematic IUPAC name Calcium ethynediide
Other names Calcium percarbide Calcium carbide Calcium dicarbide
Identifiers
CAS Number	75-20-7^Y
3D model (JSmol)	Interactive image
ChemSpider	6112^Y
ECHA InfoCard	100.000.772
EC Number	200-848-3
PubChem CID	6352
UNII	846WNV4A5F^Y
CompTox Dashboard (EPA)	DTXSID4026399
InChI InChI=1S/C2.Ca/c1-2;/q-2;+2^Y Key: UIXRSLJINYRGFQ-UHFFFAOYSA-N^Y InChI=1/C2.Ca/c1-2;/q-2;+2 Key: UIXRSLJINYRGFQ-UHFFFAOYAI
SMILES [Ca+2].[C-]#[C-]
Properties
Chemical formula	CaC₂
Molar mass	64.100 g·mol⁻¹
Appearance	White powder or colorless crystals, grey/brown/black crystals if impure
Density	2.22 g/cm³
Melting point	2,160 °C (3,920 °F; 2,430 K)
Boiling point	2,300 °C (4,170 °F; 2,570 K)
Solubility in water	Reacts to produce Acetylene
Structure
Crystal structure	Tetragonal (I phase) Monoclinic (II phase) Monoclinic (III phase)
Space group	I4/mmm (I phase) C2/c (II phase) C2/m (III phase)
Coordination geometry	6
Thermochemistry
Std molar entropy (S^⦵₂₉₈)	70 J/(mol·K)
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	−63 kJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Reacts with water to release acetylene gas
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H260
NFPA 704 (fire diamond)	1 4 2 W
Autoignition temperature	305 °C (581 °F; 578 K) (acetylene)
Related compounds
Related compounds	Strontium carbide Barium carbide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is ^YN ?) Infobox references