Calcium carbide

Calcium carbide
Names
Preferred IUPAC name
Calcium acetylide
Systematic IUPAC name
Calcium ethynediide
Other names
Calcium percarbide
Calcium carbide
Calcium dicarbide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.000.772 Edit this at Wikidata
EC Number
  • 200-848-3
UNII
  • InChI=1S/C2.Ca/c1-2;/q-2;+2 checkY
    Key: UIXRSLJINYRGFQ-UHFFFAOYSA-N checkY
  • InChI=1/C2.Ca/c1-2;/q-2;+2
    Key: UIXRSLJINYRGFQ-UHFFFAOYAI
  • [Ca+2].[C-]#[C-]
Properties
CaC2
Molar mass 64.099 g/mol
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)
Reacts to produce Acetylene
Structure[1]
Tetragonal (I phase)
Monoclinic (II phase)
Monoclinic (III phase)
I4/mmm (I phase)
C2/c (II phase)
C2/m (III phase)
6
Thermochemistry
70 J·mol−1·K−1
−63 kJ·mol−1
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Reacts with water to release acetylene gas[2]
GHS labelling:
GHS02: FlammableGHS05: Corrosive
Danger
H260
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
1
4
2
W
305 °C (581 °F; 578 K) (acetylene)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Calcium carbide, also known as calcium acetylide, is a chemical compound with the chemical formula of CaC2. Its main use industrially is in the production of acetylene and calcium cyanamide.[3]

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.[4]

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

  1. ^ Konar, Sumit; Nylén, Johanna; Svensson, Gunnar; Bernin, Diana; Edén, Mattias; Ruschewitz, Uwe; Häussermann, Ulrich (2016). "The many phases of CaC2". Journal of Solid State Chemistry. 239. Elsevier BV: 204–213. Bibcode:2016JSSCh.239..204K. doi:10.1016/j.jssc.2016.04.030. ISSN 0022-4596.
  2. ^ NFPA Hazard Rating Information for Common Chemicals. Northeastern University
  3. ^ Patnaik, Pradyot (2003). Handbook of Inorganic Chemical Compounds. McGraw-Hill. ISBN 0-07-049439-8.
  4. ^ Vincoli, Jeffrey Wayne (25 November 1996). Risk Management for Hazardous Chemicals. CRC Press. p. 429. ISBN 978-1-56670-200-3.