Ethynol

Ethynol
Names
	Systematic IUPAC name Ethynol
	Other names Ynol, ethynyl alcohol, hydroxyacetylene
Identifiers
CAS Number	32038-79-2 ;
3D model (JSmol)	Interactive image; Interactive image;
ChemSpider	110037 ;
PubChem CID	123441;
CompTox Dashboard (EPA)	DTXSID90185855 ;
	InChI InChI=1S/C2H2O/c1-2-3/h1,3H Key: QFXZANXYUCUTQH-UHFFFAOYSA-N ;
	SMILES OC#C; C#CO;
Properties
Chemical formula	C2H2O
Molar mass	42.037 g·mol−1
Density	0.981 g·cm−3
Boiling point	77.1 °C (170.8 °F; 350.2 K) @ 760mmHg
Hazards
Flash point	14.7 °C (58.5 °F; 287.8 K)
Thermochemistry
Std enthalpy of; formation (ΔfH⦵298)	41.6 kJ mol−1
Related compounds
Related compounds	Propargyl alcohol
	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

Ethynol (or hydroxyacetylene, ethynyl alcohol) is an alkyne–alcohol (ynol) with the formula C₂H₂O. It is the much-less-stable tautomer of ethenone.

At low temperature in a solid argon matrix it is possible to tautomerise ethenone to form ethynol.