Acetaldehyde
0.7904–0.7928 g·cm−3 (10 °C) Melting point −123.37 °C (−190.07 °F; 149.78 K) Boiling point 20.2 °C (68.4 °F; 293.3 K) Solubility in water soluble Solubility miscible with ethanol, ether, benzene, toluene, xylene, turpentine, acetone slightly soluble in chloroform log P -0.34 Acidity (p
Ka) 13.57 Refractive index (
nD) 1.3316 Viscosity ~0.215 at 20 °C Structure Molecular shape trigonal planar (sp²) at C1 tetrahedral (sp³) at C2 Dipole moment 2.7 D Thermochemistry Std molar entropy
So298 250 J·mol−1·K−1 Std enthalpy of formation Δf
Ho298 −166 kJ·mol−1 Hazards MSDS External MSDS GHS pictograms GHS hazard statements H224, H319, H335, H351 GHS precautionary statements P210, P261, P281, P305+351+338 EU classification Very flammable (
F+) Harmful (
Xn) Carc. Cat. 3 R-phrases R12 R36/37 R40 S-phrases (S2) S16 S33 S36/37 NFPA 704 4 2 2 Flash point −39.00 °C; −38.20 °F; 234.15 K Explosive limits 4.