Petroleum ether is characterized as a nonpolar solvent. This nonpolarity is due to its composition, which primarily consists of aliphatic hydrocarbons. These molecules have little to no dipole moment because they lack significant electronegative atoms such as oxygen or nitrogen. This feature makes petroleum ether a suitable solvent for dissolving nonpolar substances.
Furthermore, petroleum ether is considered an aprotic solvent. Aprotic solvents do not have hydrogen atoms bonded to electronegative atoms, which means they do not donate protons (H+) in a reaction. In contrast, protic solvents, such as water or alcohols, can donate protons and have hydrogen atoms attached to electronegative atoms. The absence of these characteristics in petroleum ether reaffirms its classification as an aprotic solvent.