apolaarse

Apolaarse refers to a property of molecules that describes their lack of a net electrical dipole moment. This occurs when the distribution of electrons within a molecule is symmetrical. In apolaarse molecules, the electronegativity differences between bonded atoms are either very small or non-existent, or any polar bonds are arranged in such a way that their individual dipole moments cancel each other out.

A common characteristic of apolaarse substances is their behavior in different solvents. They tend to be insoluble in polar solvents like water, which have significant dipole moments themselves. Instead, apolaarse substances dissolve well in other apolaarse solvents. This principle is often summarized by the phrase "like dissolves like."

Examples of apolaarse molecules include diatomic elements such as oxygen (O2) and nitrogen (N2), where the two identical atoms have no electronegativity difference. Hydrocarbons, like methane (CH4) and octane (C8H18), are also generally apolaarse. Even though C-H bonds have a small electronegativity difference, the symmetrical tetrahedral structure of methane leads to a cancellation of dipole moments. Similarly, the symmetrical arrangement of bonds in larger hydrocarbons results in apolaarse character.

The apolaarse nature of a molecule influences its physical properties, such as its boiling point and melting point, as well as its interactions with other molecules. These intermolecular forces, known as London dispersion forces, are the weakest type of van der Waals forces and are present in all molecules, but they are the primary forces of attraction in apolaarse substances.