Answer: The property that is characteristic of alkenes, alkynes, and aromatic hydrocarbons is that they are insoluble in water.
Alkenes, alkynes, and aromatic hydrocarbons are nonpolar hydrocarbons that do not have an electrical charge, which makes them insoluble in water. Water is a polar molecule with a partial negative charge at the oxygen atom and a partial positive charge at the hydrogen atoms. Nonpolar molecules, like alkenes, alkynes, and aromatic hydrocarbons, do not interact strongly with the polar water molecules and, therefore, do not dissolve in water.
However, alkenes, alkynes, and aromatic hydrocarbons are generally soluble in nonpolar solvents such as benzene, toluene, and hexane. This is because nonpolar solvents have similar polarities to these hydrocarbons, which allows them to dissolve and mix together.
Vapor pressure, pH, and solubility characteristics of alkenes, alkynes, and aromatic hydrocarbons depend on the specific properties of each compound and are not generally characteristic of this group of hydrocarbons.