Table 2.

Physical properties of C₄ hydrocarbons.14, 18, 43

Compound	B.p. [K]	Kinetic diameter [Å]	Polarizability [10−25 cm3]	Dipole moment[a] [×1018 esu cm]
butane	272.66	4.687	82	0.05
isobutane	261.34	5.278	81.4–82.9	0.132
1‐butene	266.92	4.46	81	0.359–0.438
cis‐2‐butene	276.87	4.94	82	0.30
trans‐2‐butene	274.03	4.31	81.82	0.00
1,3‐butadiene	268.62	4.31	86.4	0.00
isobutene	266.25	4.840	80	0.50

[a] 1 Debye=10⁻¹⁸ esu cm.