Ethenone

Ethenone

Names
IUPAC name Ethenone
Other names Carbomethene Ketene Keto-ethylene Methylene ketone Methyleneoxaethylene Oxoethylene
Properties
Chemical formula	C2H2O
Molar mass	42.037 g/mol
Appearance	Colorless gas
Odor	Pungent, penetrating
Density	0.65 g/cm3 (-60 °C)
Melting point	−150.5 °C (−238.9 °F; 122.6 K)
Boiling point	−56.1 °C (−69.0 °F; 217.1 K)
Solubility in water	Reacts
Solubility	Reacts with carboxylic acids Soluble in acetone, benzene, chloroform, ethanol Slightly soluble in diethyl ether
Thermochemistry
Std enthalpy of formation (ΔfHo298)	-87.24 kJ/mol
Hazards
Safety data sheet	CPCB
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Ethenone, or simply ketene, is an organic compound with formula C₂H₂O or H₂C=C=O. It is the simplest member of the ketene class. Ethenone is a tautomer of ethynol.

Properties

Chemical

Ethenone reacts with water to give acetic acid. Reaction with acetic acid gives acetic anhydride.

Physical

Ethenone is a colorless, toxic gas, with a strong pungent odor.

Availability

Due to its extreme toxicity, ethenone is not sold and has to be made in situ.

Preparation

Ethenone can be made by pyrolyzing acetone in oxygen-free atmosphere. Watch Doug's Lab two-part video for this procedure.

Projects

• Make acetic anhydride
• Make acetyl halide

Handling

Safety

Ethenone is extremely toxic, with a LD50 similar to that of phosgene and hydrogen cyanide.

DO NOT WORK WITH THIS CHEMICAL UNLESS YOU HAVE EXPERIENCE WORKING WITH VOLATILE LETHAL GASSES!

Storage

DO NOT STORE ETHENONE! Use it as soon as possible.

Disposal

Ethenone can be neutralized by dissolving it in an aqueous alkali solution. Perform the neutralization in a well ventilated area.

References

Relevant Sciencemadness threads

• Copper and Acetone
• keten lamp