Formic acid is a colorless liquid having a highly pungent, penetrating odor[5] at room temperature. It is miscible with water and most polar organic solvents, and is somewhat soluble in hydrocarbons. In hydrocarbons and in the vapor phase, it consists of hydrogen-bonded dimers rather than individual molecules.[6][7] Owing to its tendency to hydrogen-bond, gaseous formic acid does not obey the ideal gas law.[7] Solid formic acid (two polymorphs) consists of an effectively endless network of hydrogen-bonded formic acid molecules. This relatively complicated compound also forms a low-boiling azeotrope with water (22.4%) and liquid formic acid also tends to supercool.