3-Picoline Chemical Properties Melting point −19 °C(lit.) Boiling point 144 °C(lit.) density 0.957 g/mL at 25 °C(lit.) vapor density 3.2 (vs air) vapor pressure 4.4 mm Hg ( 20 °C) refractive index n20/D 1.504(lit.) Fp 97 °F storage temp. Flammables area