1,3-Butadiene (data page)

**Properties**
General
Name	1,3-Butadiene
CH₂=CH-CH=CH₂
Chemical formula	C₄ H₆
Molar mass	50.09 g/mol
Synonyms	butadiene, biethylene, divinyl, erythrene, vinylethylene
CAS number	106-99-0
Phase behavior
Melting point	164.3 K (-108.9 °C)
Boiling point	268.8 K (-4.4°C)
Triple point	164.2 K (-109.0°C) ? bar
Critical point	425 K (152°C) 43.2 bar
Structure
Symmetry group	C_2h
Gas properties
Δ_fH⁰	110.2 kJ/mol
S⁰	? J/mol·K
C_p	79.5 J/mol·K
Liquid properties
Δ_fH⁰	90.5 kJ/mol
S⁰	199.0 J/mol·K
C_p	123.6 J/mol·K
Liquid density	0.64 ×10³ kg/m³
Safety
Acute effects	Possible irritation to skin and mucous membranes. Inhalation of concentrated vapors causes drowsiness and CNS depression.
Chronic effects	Possible carcinogen.
Flash point	-85°C
Autoignition temperature	418°C
Explosive limits	2-12%
More info
Properties	NIST WebBook
MSDS	Hazardous Chemical Database
SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references